Displacement is the difference between two co-ordinates so the origin doesn't matter.
Explanation:
Displacement is a physical quantity that depicts the change of position in a particle, this further is measured by the difference in position vectors limiting the duration under these two limits.Displacement = Velocity × TimeInstantaneous velocity = d/dt (position vector)
d = vt + 1/2 at² is the displacement acceleration equation.
d = u + at is the velocity displacement equation.
Displacement always has continuity with velocity and Acceleration.The average velocity is 0 if the displacement is 0.
A curve plotted as a function of frequency defining the sound pressure level required to give equal loudness is?
Answer:
equal loudness curve
Explanation:
The curves of equal loudness, first established by Munson and Fletcher in 1930 and subsequently recalculated by Robinson and Dadson, show the relationship that must exist between the frequencies and intensities (or sound pressure) of two sine sounds to be perceived equally loudly. , that is, with the same loudness.
The sinusoidal sounds contained along each curve have the same loudness. This frequency dependence would be mainly due to the transfer characteristics of the external and middle ear. It should also be noted that as the sound pressure level increases, the curves become flatter, that is, the frequency dependence is smaller as the sound pressure level increases.
The loudness level of any sound (complex) is determined by comparing its loudness with that of a sinusoidal sound.
A curve plotted as a function of frequency defining the sound pressure level required to give equal loudness is known as an equal-loudness curve. These curves use the phon unit to illustrate how different sound pressure levels are needed at various frequencies for a sound to be perceived as equally loud.
Explanation:The curve plotted as a function of frequency defining the sound pressure level required to give equal loudness is known as an equal-loudness curve. These curves are critical for understanding how the human ear perceives sound at different frequencies and intensity levels, using a unit called a phon to express loudness numerically. Phons and decibels are defined to be the same at 1000 Hz, which serves as a standardized point of reference. The equal-loudness curves show that at different frequencies, different sound pressure levels are required for a sound to be perceived as equally loud. This phenomenon underlines the non-linear nature of human hearing across the frequency spectrum.
Large numbers of people have compared the loudness of sounds at different frequencies and sound intensity levels to determine these curves. Each curve is labeled with its loudness in phons, and all sounds on a given curve are perceived as equally loud. This concept is vital for various applications, including the design of audio equipment, hearing aids, and soundproofing materials, to ensure sound is produced or mitigated in a manner consistent with human loudness perception.
What is the maximum value of the resistance of the pull-up resistor, such that you avoid floating when the switch is open? pull-up
Answer:
Resistance of order of 10Kiloohms
Explanation:
Pull up resistors are essential in every microcontroller devices or digital circuits. Which helps prevent floating ( a process of not being able to determine the state of a pin) It works by allowing the state of a pin to be in either a high state or low state. A resistor is connected between the Vcc and the pin.
When the switch is open, the entire voltage flows through the resistor (V=IR). When the switch is closed the pull up resistor and the internal impedance of the pin form a voltage divider to limit the current flow.
The maximum value of a pull-up resistor to avoid floating when the switch is open is typically between 1KΩ to 10KΩ. This helps to prevent excessive current flow and quickly pulls the input pin high to avoid a floating state. Extremely high resistance values, like 1 megaohm, may cause brief floating, potentially leading to incorrect readings.
Explanation:The maximum value of the pull-up resistor, in order to avoid a floating condition when the switch is open, depends on several factors including the characteristics of the microcontroller's input pin and the voltage level of the system. However, a moderately high resistance value is often chosen in the range of 1KΩ to 10KΩ to prevent excessive current flow when the switch is closed while still pulling the input pin high quickly enough to avoid a floating state when the switch is open. Remember that a pull-up resistor's purpose is to define a state of a digital input pin when it is not otherwise driven by an external component or system.
In some cases, the maximum value of the pull-up resistor will need to be calculated based on the specifications of your particular circuit. An extremely high resistance, like 1 megaohm, can cause the input to float for a very short time, long enough that your microcontroller might read it incorrectly.
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Beginning at the NW corner of the intersection of Pine & 675, thence north 950 feet, thence west 380 feet, thence south 950 feet, thence east 380 feet. Is this an acceptable metes and bounds description?
Answer:
this description is valid for mediadle displacement, bone is an acceptable description
Explanation:
The description of a person's position must be done with a position vector. These vectors must have magnitude, a given direction and a starting point.
In the description this has a starting point corner NO of pine and 675.
Each displacement occurs with respect to the previous one, indicating the magnitude of the displacement and its direction.
After analyzing this description is valid for mediadle displacement, bone is an acceptable description
At a fabrication plant, a hot metal forging has a mass of 67.2 kg and a specific heat capacity of 438 J/(kg C°). To harden it, the forging is quenched by immersion in 786 kg of oil that has a temperature of 37.1 °C and a specific heat capacity of 2950 J/(kg C°). The final temperature of the oil and forging at thermal equilibrium is 58.3 °C.
Assuming that heat flows only between the forging and the oil, determine the initial temperature in degrees Celsius of the forging.
Answer:
Tm = 1,728.38 °C
Explanation:
mass of metal forging (Mm) = 67.2 kg
specific heat capacity of metal forging (Cm) = 438 J/kg°C
initial temperature of metal forging (Tm) = ?
final equilibrium temperature (Te) = 58.3 °C
mass of oil (Mo) = 786 kg
specific heat capacity of oil (Co) = 2950 J/kg°C
temperature of oil (To) = 37.1 °C
Mm × Cf × (Tm - Te) = Mo × Co × (Te - To)
Tm = [tex]\frac{Mo x Co x (Te - To) }{Mm x Cf}[/tex] + Te
Tm = [tex]\frac{786 x 2950 x (58.3 - 37.1) }{67.2 x 438}[/tex] + 58.3
Tm = 1,728.38 °C
An astronaut drops a ball off the edge of a crater on the Moon, where gravity is 1.6 m/s(s). If it takes 5 seconds for the ball to reach the bottom of the crater, what is the depth of the crater? (Need HELP, AAAAAAAAAAAAAAAAAAAAAA.)
Answer:
The depth of the crater is 20[m]
Explanation:
We can solve this problem using the kinematics equations, it should be noted that the negative sign of acceleration means that the drop of the object is down.
Data:
a = 1.6[m/s^2]
t = 5 [s]
[tex]y=y_{0} +v_{0} *t-\frac{1}{2} *g*(t)^{2}[/tex]
v0= 0, because there is not initial veocity
y = final distance = 0 the bottom of the crater
g = a = acceleration of the crater [m/s^2]
y0= Point where the ball was dropped. = Distance from the original point to the bottom of the crater.
[tex]y_{0} =\frac{1}{2}*1.6*(5)^{2}\\ y_{0} = 20 [m][/tex]
An electromagnetic wave has an electric field given by
E? (y,t)=[3.90×105V/mcos(ky−(1.200×1013rad/s)t)]k^
In which direction is the wave traveling?What is the wavelength of the wave?
Answer:
λ = 157 μm
Explanation:
given,
[tex]\vec{E}(y,t)=[ 3.9\times 10^5\ V/m cos(ky-(1.20\times 10^{13}\ rad/s )t)]\vec{k}[/tex]
now,
ω = 1.2 x 10¹³ rad/s
[tex]f =\dfrac{\omega}{2\pi}[/tex]
[tex]f =\dfrac{1.2\times 10^{13}}{2\pi}[/tex]
f = 1.91 x 10¹² Hz
determine the wavelength of the E M wave
[tex]\lambda = \dfrac{c}{f}[/tex]
[tex]\lambda = \dfrac{3\times 10^8}{1.91\times 10^{12}}[/tex]
λ = 1.57 x 10⁻⁴ m
λ = 157 x 10⁻⁶ m
λ = 157 μm
hence, the wavelength of the wave is equal to λ = 157 μm
Given that,
[tex]\vec{E}(y,t) = [3.9\times 10^5 \ V/mcos] (ky-(1.20\times 10^{13} \ rad/s)t)] \vec{k}[/tex]here,
[tex]\omega = 1.2\times 10^{13} \ rad/s[/tex]As we know,
→ [tex]f = \frac{\omega}{2 \pi}[/tex]
By substituting the values, we get
[tex]= \frac{1.2\times 10 ^{13}}{2 \pi}[/tex]
[tex]= 1.91\times 10^{12} \ Hz[/tex]
hence,
The wavelength will be:
→ [tex]\lambda = \frac{c}{f}[/tex]
[tex]= \frac{3\times 10^8}{1.91\times 10^{12}}[/tex]
[tex]=157\times 10^{-6} \ m[/tex]
[tex]= 157 \ \mu m[/tex]
Thus the above response is correct.
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If a solution surrounding a cell is hypotonic relative to the inside of the cell, in which direction will water move?
Answer:
If the cell is placed in a surrounding solution which is hypotonic in nature.
Then the water from outside of the cell to the inside of the cell. The water will keep on moving from the outside of the cell to the inside of the cell.
The flow of water will take place until the outside environment of the cell and the inside of the cell becomes equal.
The flow of water will take place from the outside of the cell to the inside of the cell.
Answer:
The direction of motion of water molecules will be into the cell.
Explanation:
A hypotonic solution is one which has the less concentration of solute in the solvent as compared to the solution on the other side of the semi-permeable membrane. This creates an osmotic pressure gradient across the semi-permeable membrane which is responsible for the flow of water molecules across the membrane until the concentration becomes equal for both the solutions.(A semi-permeable membrane is a sheet or a plane barrier which does not allows the molecules over certain size to pass through it. Here the membrane does not allows the molecules larger in size than that of water molecules to pass through it.)A solid cone is 10 cm high. where is its center of mass?
Answer:
The center of mass of a cone is located along a line. This line is perpendicular to the base and reaches the apex. The center of mass is a distance 3/4 of the height of the cone with respect to the apex.
Explanation:
The center of mass of a solid cone is located one-third of the way up from the base.
Explanation:The center of mass of a solid cone is located at one-third of its height from the base. In this case, the cone is 10 cm high, so the center of mass is located 10 cm * (1/3) = 3.33 cm from the base.
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Unless otherwise posted, the maximum speed limit in any urban or residential district is ____ mph.
A. 45
B. 40
C. 30
Answer:
C 30 mph
Explanation:
The speed limits in various area's can be concluded as
1. 25- 30 mph in urban residential areas and school districts.
2.55 mph on rural highways, and
3. 70 mph on rural Interstate highways.
so, the correct answer is c
boy pulls a 5.0-kg sled with a rope that makes a 60.0° angle with respect to the horizontal surface of a frozen pond. The boy pulls on the rope with a force of 10.0 N; and the sled moves with constant velocity. What is the coefficient of friction between the and the ice?
(a) 0.09
(b) 0.12
(c) 0.18
(d) 0.06
(e) 0.24
Answer:
0.1
Explanation:
mass, m = 5 kg
θ = 60°
Force, F = 10 N
velocity is constant , it means the net force is zero.
So, the component of force along the surface is equal to the friction force
FCosθ = friction force
10 x cos 60 = μ x m x g
where, μ is the coefficient of friction
5 = μ x 5 x 9.8
μ = 0.1
Thus, the coefficient of friction is 0.1
According to quantum physics, measuring velocity of a tiny particle with an electromagnet
A. Has no effect on the velocity of the particle.B. Affects the velocity of the particle.
Answer:
Option A.
Explanation:
In quantum physics there is a law to relate the position and the momentum of the particle, it says that if we know with precision where is a quantum particle, we can not know the momentum of this particle, in other words, the velocity of the particle. So, when we measure the velocity of the particle we find the correct value of the particle, but we can not determine with accuracy where is the particle. This law is known as the Heisenberg's uncertainty principle and, its expressed as follows:
[tex] \Delta x \Delta p \geq \frac{h}{4 \pi} [/tex]
where Δx: is the position's uncertainty, Δp: is the momentum's uncertainty and h: is the Planck constant.
Therefore, the correct answer is A: measuring the velocity of a tiny particle with an electromagnet has no effect on the velocity of the particle. It only affects the determination of the particle's position.
I hope it helps you!
Technician A says that low compression on a single cylinder will cause an engine not to start. Technician B says that low compression on a single cylinder means that the engine can be fixed with a tune-up. Who is correct?
Tech A
Tech B
Both A and B
Neither A nor B
Answer:
Technician B
Explanation:
Car engine compression refers to when air and gas are mixed together in the cylinders of an engine. This process is required for the car to move and function. If there are any problems with the compression process, then you can expect to experience all kinds of car problems.
It will be easy to tell when you have a low compression problem because you may experience a misfire when you try to start the engine. Either that or the engine will offer poor performance as you’re driving the vehicle down the road. The worst-case scenario would be the car not starting if all the cylinders have no compression.
Generally speaking, if you have low compression in one(single) cylinder, the engine will start but you’ll likely experience misfires and your vehicle will run rough. If you experience no compression in ALL cylinders, your engine simply won’t start. This rule out A statement.
An engine tune-up is a exercise for engines to undergo regularly. It is a way of making a car's work at the level and standard intended by the car manufacturer when the car was first made. All manufacturers will stipulate a schedule of when a car will required an engine tune-up to ensure that a car runs at it's most efficient
Engine tune-up are imperative to ensure that all the power and efficiency that your car is capable are being reached . This bring the answer to the question to Tech B.
The engine in an imaginary sports car can provide constant power to the wheels over a range of speeds from 0 to 70 miles per hour (mph). At full power, the car can accelerate from zero to 32.0mph in time 1.10s .A)At full power, how long would it take for the car to accelerate from 0 to 64.0mph ? Neglect friction and air resistance. =4.40sPart BA more realistic car would cause the wheels to spin in a manner that would result in the ground pushing it forward with a constant force (in contrast to the constant power in Part A). If such a sports car went from zero to 32.0mph in time 1.10s , how long would it take to go from zero to 64.0mph ?am not sure how to do part B
Answer:
a) 4.40 s
b) 2.20 s
Explanation:
Given parameters are:
At constant power ,
initial speed of the car, [tex]v_0=0[/tex]
final speed of the car, [tex]v=32[/tex] mph
At full power,
initial speed of the car, [tex]v_0=0[/tex]
final speed of the car, [tex]v=64[/tex] mph
a)
At constant power, [tex]KE = \frac{1}{2} mv^2[/tex]
At full power, [tex]KE = \frac{1}{2} m(2v)^2[/tex]
So [tex]KE_f = 4KE_i[/tex]
So, time to reach 64 mph speed is 4 times more than the initial time
[tex]t = 4*1.10 =4.40[/tex] s
b)
[tex]v=v_0+at\\a=\frac{v-v_0}{t}=\frac{32-0}{1.1/3600}=104727.27[/tex] [tex]miles/hours^2[/tex]
For final 64 mph speed,
[tex]v=v_0+at\\t=\frac{v-v_0}{a}=\frac{64-0}{104727.27} = 6.111*10^{-4}[/tex] [tex]hours[/tex] = [tex]6.111*10^{-4}*3600=2.20[/tex] s
Object A has a position as a function of time given by rA(t) = (3.00 m/s)t i ^ + (1.00 m/s2)t2j^. Object B has a position as a function of time given byrB(t) = (4.00 m/s)ti^ + (-1.00 m/s2)t2j^. All quantities are SI units. What is the distance between object A and object B at time t = 3.00 s?A) 3.46 m B) 15.0 m C) 18.3 m D) 34.6 m E) 29.8 m
Explanation:
Given that
[tex]rA(t)=(3.00 m/s)t\hat{i}+ (1.00 m/s^2)t^2\hat{j}\texttt{ and }rB(t)=(4.00 m/s)t\hat{i}+ (-1.00 m/s^2)t^2\hat{j}[/tex]
We need to find distance when t = 3 s
Substituting t = 3 s
[tex]rA(t)=(3.00 m/s)\times 3\hat{i}+ (1.00 m/s^2)\times 3^2\hat{j}=9\hat{i}+9\hat{j}\\\\rB(t)=(4.00 m/s)\times 3\hat{i}+ (-1.00 m/s^2)\times 3^2\hat{j}=12\hat{i}-9\hat{j}[/tex]
[tex]\texttt{Displacement = }12\hat{i}-9\hat{j}-(9\hat{i}+9\hat{j})=3\hat{i}-18\hat{j}[/tex]
[tex]\texttt{Magnitude = }\sqrt{3^2+(-18)^2}=18.3m[/tex]
Option C is the correct answer.
The distance between object A and object B is approximately 18.248 meters. (Choice C)
How to calculate the distance between two objects
In this question we must apply the concepts of vector difference, dot product and norm to determine the distance between objects A and B, in meters:
[tex]r_{B/A} = \sqrt{(\vec r_{B}-\vec r_{A})\,\bullet\,(\vec r_{B}-\vec r_{A})}[/tex] (1)
Where:
[tex]\vec r_{A}[/tex] - Vector distance of object A, in meters.[tex]\vec r_{B}[/tex] - Vector distance of object B, in meters. [tex]r_{B/A}[/tex] - Distance of B relative to A, in meters.If we know that [tex]\vec r_{A} = (3\cdot t, t^{2})\,\left[m\right][/tex], [tex]\vec r_{B} = (4\cdot t,-t^{2})\,\left[m\right][/tex] and [tex]t = 3\,s[/tex], then the distance of B relative to A is:
[tex]r_{B/A}=\sqrt{t^{2}+4\cdot t^{4}}[/tex]
[tex]r_{B/A} = t\cdot \sqrt{1+4\cdot t^{2}}[/tex]
[tex]r_{B/A} = 3\cdot \sqrt{1+4\cdot 3^{2}}[/tex]
[tex]r_{B/A} \approx 18.248\,m[/tex]
The distance between object A and object B is approximately 18.248 meters. (Choice C) [tex]\blacksquare[/tex]
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Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. The greater force on the rope is exerted by
A. Arnold, of course
B. Suzie, surprisingly
C. both the same, interestingly enough
Answer:
The greater force on the rope is exerted by:
C. both the same, interestingly enough
Explanation:
The option c is correct as the rope is mass-less. Both Arnold and Suzie are pulling hard on opposite ends. But the tension of the rope is same at every point so that means both are exerting the same force on both ends of rope.The analogy for the given situation is that as when a vehicle moves on a road, the force exerted by the wheel of vehicle on the road is equal to the force exerted by the road on the wheel of vehicle.The options A and B can be possible if anyone of them exert more power on the ground through feet in this way, one can exert more force and can win.A ray of light in air is incident upon a glass plate at an angle of 45°. The angle of refraction of the ray in the glass is 30°. What is the index of refraction of the glass?
Answer:
Explanation:
Laws of refraction:
(a) The incident ray, the refracted ray and the normal at the point of incident all lies in the same plane
(b) The ratio of the sine of incident to the sine of refraction is a constant for a given pair of media, which is the refractive index of the second medium with respect to the first medium. The is also called Snell's law
from Snell's law,
Index of refraction of the glass = sini/sinr.............. Equation 1
where i = incident angle, r = angle of refraction.
given: i = 45°, r = 30°
Substituting these values into equation 1,
Index of refraction of the glass = sin45°/sin30°
Index of refraction of the glass = (1/√2)/(1/2)
Index of refraction of the glass = 2/√2
Index of refraction of the glass = √2.
Therefore, The Index of refraction of the glass = √2.
Final answer:
To calculate the index of refraction of the glass, we apply Snell's Law, resulting in an index of refraction of approximately 1.41.
Explanation:
To find the index of refraction of the glass, we can use Snell's Law, which relates the angles of incidence and refraction to the indices of refraction of the two media. Snell's Law states:
n1 * sin(θ1) = n2 * sin(θ2),
where n1 and n2 are the indices of refraction of the first and second media (air and glass, respectively), and θ1 and θ2 are the angles of incidence and refraction. Given that the index of refraction of air is approximately 1 (since it's very close to a vacuum) and using the provided angles (45° and 30°), the calculation will look like this:
1 * sin(45°) = n2 * sin(30°)
Which simplifies to:
1 * √2/2 = n2 * 1/2
After calculating, we find:
n2 = √2
Thus, the index of refraction of the glass is √2, which is approximately 1.41.
You have an empty 20 oz. soda bottle and you blow air over the opening to excite a fundamental standing wave. Now, you slice off the bottom of the bottle (it’s plastic) without changing its length very much. You blow over the opening and excite a fundamental standing wave in the bottle with its bottom end open. The frequency of the standing wave in the second case:______________________________.
Answer:
The frequency of the standing wave in the second case is higher than that in the first case
Explanation:
The frequency and wavelength of a wave are related.
The moment you sliced the bottle, you've reduced the wavelength of the bottle.
When wavelength decreases, frequency increases and vice versa.
So, When frequency increases in the second case, more wave crests pass a fixed point each second. That means the wavelength shortens. So, as frequency increases, wavelength decreases. The opposite is also true—as frequency decreases, wavelength increases.
A stone is thrown with a speed v0 and returns to earth, as the drawing shows. Ignore friction and air resistance, and consider the initial and final locations of the stone. Which one of the following correctly describes the change ΔPE in the gravitational potential energy and the change ΔKE in the kinetic energy of the stone as it moves from its initial to its final location?
A. ΔPE = 0 J and ΔKE = 0 J
B. ΔPE is positive and ΔKE is negative
C. ΔPE = 0 J and ΔKE is positive
D. ΔPE is negative and ΔKE is positive
E. ΔPE = 0 J and ΔKE is negative
Answer:
If the stone is thrown from the ground, the correct answer is A. If it is thrown from a height h, the correct answer is D.
Explanation:
Hi there!
I can´t see the drawing but let´s assume that initially, the stone is on the ground level. If that is the case, initially, the potential energy will be zero and when it returns to Earth it will also be zero. The potential energy depends on the height of the stone. If the final and initial height of the stone is zero, then the change in potential energy will also be zero:
ΔPE = final PE - initial PE
ΔPE = m · g · hf - m · g · hi (where hf and hi are the final and initial height respectively)
ΔPE = m · g (hf - hi)
ΔPE = m · g (0)
ΔPE = 0
Initially, the kinetic energy (KE) of the stone is the following:
KE = 1/2 · m · v0²
As the stone goes up, the kinetic energy is transformed into potential energy; but as the stone starts to fall, the acquired potential energy is transformed again into kinetic energy, so that the final and initial kinetic energy of the stone is the same.
Then:
ΔKE = final KE - initial KE = 0 (because final KE = initial KE).
Then, the correct answer is A.
Always ΔKE = -ΔPE due to the conservation of energy. Potential energy can´t be acquired by the stone if there is no loss of kinetic energy and vice-versa.
Let´s assume now that the stone is thrown from a height hi to the ground.
The final potential energy will be zero (becuase h = 0) but the initial PE will be:
PE = m · g · h1
Then:
ΔPE = final PE - initial PE = 0 - m · g · h1
Then ΔPE will be negative.
The initial kinetic energy will be:
KE = 1/2 · m · v0²
But the final kinetic energy will be equal to the initial kinetic energy plus the loss of potential energy (remember: if potential energy decreases, another type of energy has to increase, in this case, kinetic energy and vice-versa):
ΔKE = final KE - initial KE
ΔKE = 1/2 · m · v0² + m · g · h1 - 1/2 · m · v0²
ΔKE = m · g · h1
Then ΔKE will be positive and the correct answer would be D.
Evidence that the cosmic background radiation really is the remnant of a Big Bang comes from predicting characteristics of remnant radiation from the Big Bang and comparing these predictions with observations. Four of the five statements below are real. Which one is fictitious?
Answer:
B) The cosmic background radiation is expected to contain spectral lines of hydrogen and helium, and it does.
Explanation:
An electron is accelerated by a potential difference of 50v, what is the de broglie wavelength?
Answer:
[tex]1.73553\times 10^{-10}\ m[/tex]
Explanation:
h = Planck's constant = [tex]6.626\times 10^{-34}\ m^2kg/s[/tex]
K = Potential difference = 50 V
m = Mass of electron = [tex]9.11\times 10^{-31}\ kg[/tex]
The de broglie wavelength is given by
[tex]\lambda=\dfrac{h}{\sqrt{2mK}}\\\Rightarrow \lambda=\dfrac{6.626\times 10^{-34}}{\sqrt{2\times 9.11\times 10^{-31}\times 50\times 1.6\times 10^{-19}}}\\\Rightarrow \lambda=1.73553\times 10^{-10}\ m[/tex]
The wavelength is [tex]1.73553\times 10^{-10}\ m[/tex]
Which wavelengths of light drive the highest rates of photosynthesis?
Answer:
400-450 nm and 670-680 nm
Explanation:
Which wavelengths of light drive the highest rates of photosynthesis?
400-450 nm and 670-680 nm
Light in the violet-blue and red portions of the spectrum is most effective in driving photosynthesis
photosynthesis is the process through which green plant manufacture there food through sunlight, they synthesize nutrient in the this process through chlorophyll thereby releasing oxygen as a bye-product. a spectrum contains 7 colours combined . the violet-blue and red portions of the spectrum is most effective
Two train whistles have identical frequencies of 1.64 102 Hz. When one train is at rest in the station and the other is moving nearby, a commuter standing on the station platform hears beats with a frequency of 4.00 beats/s when the whistles operate together. What are the two possible speeds that the moving train can have?
Answer:
Vs = 6.73 m/s or Vs = 16.3 m/s
Explanation:
frequency of the trains whistle (f) = 1.64 x 10^{2} Hz = 164 Hz
frequency of beats heard = 4 beats/s = 4 Hz
velocity of the stationary train (Vr) = 0
velocity of sound in air (V) = 343 m/s
velocity of the moving train (Vs) = ?
we can get the velocity of the moving train from the formula below
Fn = f x [tex]\frac{V + Vr}{V - Vs}[/tex] ...equation 1
where Fn = net frequency
case one - assuming the train is approaching the station Fn = 164 + 4 = 168 Hzsubstituting the known values into equation 1
168 = 164 x [tex]\frac{343 + 0}{343 - Vs}[/tex]
1.02 = [tex]\frac{343 + 0}{343 - Vs}[/tex]
Vs = [tex]343 - \frac{343 + 0}{1.02}[/tex]
Vs = 6.73 m/s
case two - assuming the train is leaving the station Fn = 164 - 4 = 160 Hzsubstituting the known values into equation 1
168 = 160 x [tex]\frac{343 + 0}{343 - Vs}[/tex]
1.05 = [tex]\frac{343 + 0}{343 - Vs}[/tex]
Vs = [tex]343 - \frac{343 + 0}{1.05}[/tex]
Vs = 16.3 m/s
Slow moving vehicles must display ___________ emblem at the rear to warn of their low speed.A. a red square B. a yellow triangular C. an orange triangular
Answer:
option C
Explanation:
The correct answer is option C
An orange triangular sign on the rear of the vehicle will show that the vehicle will move at a slow speed.
Warning Sign is an important method of conveying the message. Warning sign helps for the smooth movement of the traffic.
A car with an orange sign on the rear will inform the fellow driver that the vehicle is slow and they can overtake it.
Assume that the earth is a uniform sphere and that its path around the sun is circular.
(a) Calculate the kinetic energy that the earth has because of its rotation about its own axis. For comparison, the total energy used in the United States in one year is about 9.33 multiplied by 109 J.
(b) Calculate the kinetic energy that the earth has because of its motion around the sun.
Explanationhe rotational kinetic energy is
[tex]K_{r} =\frac{1}{2} Iω^{2}[/tex]
The moment of inertia I for a sphere is ( 2 / 5 ) m r ^2
. Substituting this in the equation yields
Kr=1/2( ( 2 / 5 ) m r ^2 )([tex](\frac{v}{r})^{2}[/tex]
1/5mv^2
1/5*5.97 × 10 ^24 *(2[tex]\pi[/tex]*6.38*10^6/86400)^2
2.57 × 10 ^29 J
b. kinetic energy of the sun
K.E=1/2*mv^2
the distance from the earth to the sun is given as
.
Answer:
a. 7.43 × 10³⁴ J b. 3.51 × 10³⁸ J
Explanation:
a. The gravitational force of attraction of a body on the surface of the earth equals the centripetal force on it due to the earth.
So, GMm/R² = mRω²
ω = √(GM/R³) where ω = angular speed of the earth. M = mass of earth = 5.972 × 10²⁴ kg, R = radius of earth = 6.4 × 10⁶ m and G = gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg²
The rotational kinetic energy of earth K.E = 1/2Iω² where I = rotational inertia = 2/5MR²
K.E = 1/2Iω²
= 1/2 × 2/5MR² × GM/R³
= GM²/5R
= 6.67 × 10⁻¹¹ Nm²/kg² × (5.972 × 10²⁴ kg)² /(6.4 × 10⁶ m × 5)
= 7.43 × 10³⁴ J
b. Similarly, the rotational kinetic energy of the earth around the sun is
K.E = GM²/5R where M = mass of sun = 1.989 × 10³⁰ kg and R = distance of earth from sun = 1.5047 × 10¹¹ m
K.E = GM²/5R
= 6.67 × 10⁻¹¹ Nm²/kg² × (1.989 × 10³⁰ kg)² / (1.5047 × 10¹¹ m × 5)
= 3.5073 × 10³⁸ J ≅ 3.51 × 10³⁸ J
The element lead (Pb) has a density 11.3 times that of water. Copper (Cu) has a density 7.9 times the density of water. A 5 kg mass of lead and a 5 kg mass of copper are both completely submerged in a bucket of water. Which mass has the LARGER buoyant force acting on it?
A) The buoyant force on the lead mass is larger.
B) The buoyant force on the copper mass is larger.
C) The buoyant force is the same on both masses.
Answer:
The answer is B
Explanation:
Density of the element lead (Pb) is:
[tex]d_{Pb} =11,3kg/dm^3[/tex]
Density of the element Copper (Cu) is:
[tex]d_{Cu} =7,9kg/dm^3[/tex]
First we need o find the volume of both materials:
[tex]V_{Pb}=5/11,3=440cm^3[/tex]
[tex]V_{Cu}=5/7,9=630cm^3[/tex]
And the buoyant forces on elements are:
[tex]P_{Pb}=440*1*9,81/1000=4,32N[/tex]
[tex]P_{Pb}=630*1*9,81/1000=6,18N[/tex]
At an uncontrolled intersection, when must the car on the right yield to the car on the left?
Answer: the car on the right should yield to the car that arrived first. That is When the car on the left arrives first
Explanation:
It must be noted that the law did not grant the 'right-of-way'. The law only says when the right of way must be yielded. The law does state who must yield the right of way neither does the law give right of way to anyone.
Yielding the right of way to another vehicle simply means that you are letting them go before you in a traffic situation.
Therefore, When two vehicles approaches an intersection without no traffic signs or signals, (that is, an uncontrolled intersection) the two vehicles must slow down. Always Yield to vehicles already in the uncontrolled intersection and drivers who arrive at the uncontrolled intersection before you.
The vehicle on the left should always yield to the right of the way to the vehicle on the right. The driver with ''right-of-way'' must pay attention to avoid a collision.
In 2014, a space probe approached the rocky core of the comet Churyumov–Gerasimenko, which is only a few km in diameter. The probe then entered orbit around the comet at a distance of 30 km. The comet was found to have a mass of 1.0 * 10^13 kg. What was the orbital period of the probe around the comet, in earth days?
Answer: 14.62 Earth days
Explanation:
This problem can be solved by Kepler’s Third Law of Planetary motion:
[tex]T=2 \pi \sqrt{\frac{a^{3}}{GM}}[/tex]
Where:
[tex]T[/tex] is the period of the probe
[tex]G=6.674(10)^{-11}\frac{m^{3}}{kgs^{2}}[/tex] is the Gravitational Constant
[tex]M=1(10)^{13} kg[/tex] is the mass of the comet Churyumov–Gerasimenko
[tex]a=30 km \frac{1000 m}{1 km}=30000 m[/tex] is the semimajor axis of the orbit the probe described around the comet (assuming it is a circular orbit, the semimajor axis is equal to the radius of the orbit)
[tex]T=2 \pi \sqrt{\frac{(30000 m)^{3}}{(6.674(10)^{-11}\frac{m^{3}}{kgs^{2}})(1(10)^{13} kg)}}[/tex]
[tex]T=1,263,771.768 s \frac{1 h}{3600 s} \frac{1 Earth-day}{24 h}=14.62 Earth-days[/tex]
Hence, the orbital period of the probe is 14.62 Earth days.
The orbital period of the Rosetta space probe, in orbit around the comet Churyumov–Gerasimenko in 2014, is calculated to be approximately 0.178 Earth days using Kepler's Third Law of Planetary Motion and given values.
Explanation:This question pertains to the calculation of the orbital period of the Rosetta space probe when it entered orbit around the comet Churyumov–Gerasimenko in 2014. First, we establish the gravitational constant (G) as approximately 6.674 × 10^-11 m^3 kg^-1 s^-2. To calculate the orbital period of an object in orbit around a celestial body, we can use Kepler's Third Law of Planetary Motion which states the square of the orbital period T is proportional to the cube of the semi-major axis a. Rearranging this law and substituting, we get T = 2π sqrt(a^3/(G*M)). Applying the given values, we get T = 2π sqrt((30*10^3 m)^3/(6.674 × 10^-11 m^3 kg^-1 s^-2*1.0*10^13 kg)) = 15378 seconds or approximately 0.178 days.
Learn more about Orbital Period Calculation here:https://brainly.com/question/1766066
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Which of the following is defined as an area of the body surface that is innervated by a single spinal nerve?
A. Transverse process
B. Malar
C. Dermatome
D. Spinous process
Answer:
Dermatome. (Ans. C).
Explanation:
Dermatome is defined as the area of the human anatomy skin which is supplied by single spinal sensory nerve root. At the spinal cord these spinal sensory nerve enter the nerve root, and the branches of spinal sensory reach to the periphery of the body.
The sensory nerve which is present in the periphery of the body are the type of nerve which helps to transmit signals from sensation such as pain, temperature, etc. to the spinal cord from some specific area of the anatomy.
A ball is fixed to the end of a string, which is attached to the ceiling at point P. As the drawing shows, the ball is projected downward at A with the launch speed v0. Traveling on a circular path, the ball comes to a halt at point B. What enables the ball to reach point B, which is above point A? Ignore friction and air resistance.
Answer:
The ball's initial kinetic energy
The ball comes to a stop at B. At this point its initial kinetic energy is converted into potential energy
Explanation:
A ball is fixed to the end of a string, which is attached to the ceiling at point P. As the drawing shows, the ball is projected downward at A with the launch speed v0. Traveling on a circular path, the ball comes to a halt at point B. What enables the ball to reach point B, which is above point A? Ignore friction and air resistance.
From conservation of energy which states that energy can neither be created nor be destroyed, but can be transformed from one form to another.
Ki+Ui=Kf+Uf
Ki=initial kinetic energy
Ui=initial potential energy
Kf=final kinetic energy
Uf=final potential energy
we know that [tex]\frac{1}{2} mu^{2} +mgha=\frac{1}{2} mv^{2} +mghb[/tex]
m=mass of the ball
ha=downward height a
hb=upward height b
u=initial velocity u
v=final velocity v, which is 0
g=acceleration due to gravity
v=0 at final velocity
1/2mu^2+mgha=0+1/2mv^2
ha=hb+Ki/mh
From the above equation, we can conclude that the ball's initial kinetic energy is responsible for making the ball reach point B.
Point B is higher than point A from the motion gained by the ball
ListenA person on a ledge throws a ball vertically downward, striking the ground below the ledge with 200 joules of kinetic energy. The person then throws an identical ball vertically upward at the same initial speed from the same point. What is the kinetic energy of the second ball when it hits the ground? [Neglect friction.]
A. 200 J
B. 400 J
C. less than 200 J
D.more than 400 J
Answer:
A. 200 J
Explanation:
The initial kinetic energy depends on the initial speed, while the gravitational potential energy depends on the height, both balls are thrown with the same initial speed and from the same height. Therefore, due to the law of conservation of energy, the balls must have the same mechanical energy (the sum of both energies) when both impact the ground. Since the potential energy is zero at this point, its final kinetic energy must also be the same.
The second ball, thrown vertically upward, will have kinetic energy of 200 joules when it hits the ground, making option A. the correct option.
To answer this question, let's analyze the energy transformations involved. When the ball is thrown downward, it strikes the ground with 200 joules of kinetic energy.
This energy comes from the initial throw plus the gravitational potential energy converted during its fall.
When the second ball is thrown upward, it initially gains gravitational potential energy as it rises, then this potential energy is converted back to kinetic energy as it falls back down.
The initial speed given to the ball in both scenarios is the same, meaning the total energy input into the system is identical for both throws.
Since both balls have the same initial speed and both experience the same gravitational acceleration, the second ball will also have 200 joules of kinetic energy when it hits the ground.
Therefore, the correct answer is A. 200 J.