Dan's velocity is calculated by dividing his total displacement of 15 km west by the total time of 45 minutes, which is equivalent to 0.75 hours, hence his velocity is 20 km/h west.
Explanation:The student asks about Dan's velocity after biking 10 km west and then another 5 km west in a total time of 45 minutes. To find the average velocity, we need to calculate the total displacement over the total time. Since Dan's travel direction is consistent (west), the total displacement is simply the sum of the two distances. So, his displacement is 10 km + 5 km = 15 km west. To get the velocity, we divide the displacement by the time in hours. First, we convert 45 minutes into hours by dividing by 60, which gives us 0.75 hours. Hence, Dan's velocity is 15 km / 0.75 h = 20 km/h west.
You hear the engine roaring on a race car at the starting line.Predict the changes in sound as the race starts and approaches the camera
A.the sound of the engine will get louder and pitch lower
B.the sound of the engine will get louder and pitch higher
C.the sound is determined by the car and it will not change in anyway
D.the sound of an engine will get louder but the pitch will not change
The answer is B because if you seen a movie you would see it happen
The change in the car engine's sound as it approaches the camera can be explained by the Doppler Effect. The sound will get louder, and the pitch will get higher.
Explanation:This question pertains to the Doppler effect observed in sound waves. When a race car starts its engines, the sound of the car's engine roaring is heard at a certain pitch. As the car begins to move towards you, the source of the sound gets closer and the waves reach your ear more frequently. This translates into our perception as a higher pitch. So, the correct answer is B. The sound of the engine will get louder and pitch higher as the car approaches the camera.
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alex goes shopping . he buys 2 hats that hat cost the same price and a scarfthat cost $17. total he spent $35. how much did each hat cost
35-17=18
18/2=9
9+9+17=35
Each hat cost him 9 dollars.
What is the voltage in a circuit if the current is 6 Amps and resistance is 6 ohms
In physics, Ohm's law is used to calculate the voltage in a circuit. With the current of 6 Amps and the resistance of 6 ohms, the voltage would be 36 Volts.
Explanation:The subject matter of the question is related to a fundamental concept in Physics, called Ohm's law. Ohm's law states that the voltage (V) across a resistor is directly proportional to the current (I) through it, and the constant of proportionality is the resistance (R). It is represented by the formula V = I * R.
In your case, if the current (I) is 6 Amps and the resistance (R) is 6 ohms, using Ohm's law, the voltage (V) can be calculated as the product of current and resistance. Therefore, V = I* R = 6 Amps * 6 Ohms = 36 Volts.
So, the voltage in the circuit is 36 Volts.
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Which of the following shows a car that is increasing in speed
an 1150kg elevator moving down speeds up at a rate of 3.5m/s. what is the tension in the supporting cables?
Answer:
The tension force in the supporting cables is 7245N
Explanation:
There are two forces acting on the elevator: the force of gravity pointing down (+) with magnitude (elevator mass) x (gravitational acceleration), and the tension force of the cable pointing up (-) with an unknown magnitude F. The net force is the sum of these forces:
[tex]F_{net} = F_g - F = m\cdot g - F\\[/tex]
We are given the resulting acceleration along with the mass, i.e., we know the net force, allowing us to solve for F:
[tex]1150kg\cdot 3.5\frac{m}{s^2}= 1150kg \cdot 9.8\frac{m}{s^2}-F\\\implies F = 1150kg\cdot(9.8-3.5)\frac{m}{s^2}= 7245N[/tex]
The tension force F in the supporting cables is 7245N
If you throw a ball to your friend, the ball ____________.
a. exerts two forces against your hand
b. exerts a force against your hand
c. exerts a force in the same direction as the force from your hand
d. exerts no forces
Answer:
B
Explanation:
How much force is needed to accelerate a 1,800kg car at rate of 1.5 m/s2?
Given data:
acceleration (a) = 1.5 m/s² ,
mass (m) = 1800 Kg ,
Determine F = ?
From Newtons II law
F = m.a N
= 1800× 1.5
= 2700 N
2700 N force needed to accelerate the car
Answer: 2700 N force needed to accelerate the car
Explanation:
F = m.a N
= 1800× 1.5
= 2700 N
In a heat engine, if 700 j of heat enters the system, and the piston does 400 j of work, what is the final internal energy of the system if the initial energy is 1,200 j?
A 1,100 J
B 300 J
C 1,500 J
D 900 J
Given that
Heat (Q) = 700 J ,
Work (W) = 400 J ,
What is the final internal energy of the system (u₂) = ?
given (u₁) = 1200 J
we know that ΔU = Q - W Joules,
(U₂ - 1100) = 700 - 400
U₂ = 300 +1100
= 1400 J
The final internal energy is 1400 J
1. A merging traffic sign is an example of a _____ sign.
A merging traffic sign is an example of a warning sign in traffic control. It warns that two separate streams of traffic will be converging into one lane, helping to manage traffic flow and prevent accidents.
Explanation:A merging traffic sign is an example of a warning sign. Warning signs are important in traffic control as they signal upcoming hazards so that drivers can prepare and react accordingly. In the case of a merging traffic sign, it indicates that two separate streams of traffic will be converging into one lane.
Understanding this sign is vital to maintain road safety. Think of it like when many vehicles speed through an intersection without regard to the posted speed limit. A traffic signal is installed to manage the flow of vehicles and prevent possible accidents. That's the same concept with a merging traffic sign – it signals drivers to prepare for incoming vehicles from another lane and take appropriate action to prevent collisions.
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a sphere with a mass of 12 g has a radius measuring 2 cm. what is its density
Formula for density is
D = mass/volume
So...
Answer: 0.3479 g/cm^3
hope this helps!
The density of the sphere is approximately 3.58×10⁶ g/m³ or 3.58g/cm³.
To calculate the density (ρ) of an object, you can use the formula:
ρ= 4/3 πr³
where m is the mass of the object and r is its radius.
In this case, the mass of the sphere is m=12g and the radius is r=2cm (r=0.02m in SI units).
Plugging in the values:
ρ= 12g / 4/3 π(0.02m)³
First, calculate the volume of the sphere:
Volume= 4/3 π(0.02m)³
Volume≈3.35×10⁻⁶ m³
Now, divide the mass by the volume to find the density:
ρ= 12g / 3.35×10⁻⁶m³
ρ≈3.58×10⁶ g/m³
Therefore, the density of the sphere is approximately 3.58×10⁶ g/m³ or 3.58g/cm³.
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compare the mass of block A, the mass of block B is:
The mass of Block-B is DOUBLE the mass of Block-A. (choice-a)
The mass of Block-B is twice the mass of Block-A and the mass of products = mass of reactants. This question asks us about the law of conservation of mass. Thus, option A is correct.
What is law of Conservation of Mass?The law of conservation of mass states that matter can neither be created nor destroyed but can be transformed form one state or form to another. This is the basics of science which implies that whatever matter we have, it was created from something before it was converted into what we have at the moment.
However, this law does not hold nuclear reactions because they undergo changes in the core of the matter which can change the proton of that same matter or neutron from one element to another. This is to say that in nuclear reactions, matter can be created and it can also be destroyed.
Therefore, The answer to this problem is mass of products = mass of reactants and this question asks us about the law of conservation of mass. Thus, option A is correct.
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The government has declared that a hurricane is likely to hit the East Coast. Which government division is part of ACF and provides guidance to citizens?
A.
Job Opportunities for Low-Income Individuals
B.
Office of Human Services Emergency Preparedness and Response
C.
Assets for Independence
D.
Low-Income Home Energy Assistance Program
The Answer is B) Office of Human Services Emergency Preparedness and Response
In optics, a diffraction ___________ is an optical component with a periodic structure, which splits and diffracts light into several beams traveling in different directions
Answer:
grating
Explanation:
Diffraction is a phenomenon in which light bends at the edges of an object because of which light falls even in the shadow region.
Diffraction grating consists of thousands of slits through which the light splits. The diffracted light travels in different directions and forms a alternate dark and bright fringes.
(50 POINTS) Set the ball and the barrier about two feet apart on the table. Grasp both ends of the ruler. Push the ball using the center of the ruler so the ball rolls, hits the barrier, and rebounds from it. Describe the motion of the ball as it moves.
Answer:
Kinetic energy
Explanation:
kinetic energy is the energy of motion. When something is moving it would be in motion so it would have kinetic energy.
Answer:
When an object, in your example, a ball, rolls (with rolling friction) bounces off of another surface, the force from the barrier is transferred into the ball causing it to roll back. (Newton’s third law)
Explanation:
A police car is parked by the side of a highway and it’s siren emits a sound measuring 750Hz. As you approach the police car from a distance, you hear a change in the sound. The change in the sounds
Answer:
The frequency of the sound increases
Explanation:
This phenomenon is known as Doppler effect, and it occurs when the observer is moving relative to the source of the sound (as in this case, sine you are moving towards the police car).
When you are moving towards the source of the sound, the frequency of the siren appears to increase, according to the formula:
[tex]f'=\frac{v+v_o}{v}f[/tex]
where
f' is the apparent frequency of the sound
v is the speed of the sound wave
[tex]v_o[/tex] is the speed of the observer relative to the source, and it is positive if the observer is approaching the source, or negative if the observer is moving away
f is the real frequency of the sound (in this case, 750 Hz)
Plz help i need this is due in 45 mins ty
Figure 1
Speed is a scalar quantity, It has only magnitude but no direction. It is defined as rate of change of distance.
Mathematically, speed = distance÷time
S = d ÷ t
S = 2560 ÷ 60
S = 42.67 m/s.
Bits:
Speed is a scalar quantity, that describes only the magnitude (42.67 m/s) of the rate of change of an objects distance. Determine the objects speed requires a unit of distance per unit of time
Figure 2
Velocity is a vector quantity, It has both magnitude and direction. It is defined as rate of change of displacement.
Mathematically, Velocity = Displacement ÷ time
V = 75 ÷ 1.5
V = 50 Km/h.
Velocity is a Vector quantity that describes both the magnitude and direction of the rate of change of objects displacement plus it describes its position. An objects overall change in position is known as its Displacement per unit time.
The center on a high school basketball team wants to increase the maximum height of his jump. What statement correctly describes how he could achieve this goal?
Jumping with more acceleration
Answer:
Explanation:
D) Jumping with greater initial velocity would increase the height of his jump.
If a 1000 kg cannon at initialy at rest fires a 10 kg cannonball at 200 m/s, what is the final velocity of the cannon?
Since the whole cannon AND the lead cannonball inside it are starting out motionless, there's no momentum before the shot.
We know that momentum is conserved, so the total momentum after the shot must also be zero. This tells us that whatever momentum the ball carries away in THAT ===> direction, the cannon itself will have the same amount of momentum in THIS <=== direction. That way, they'll add up to zero like we need them to.
The physics we need: Momentum = (mass) x (velocity)
OK. All students hearing protection ready now. Ready on the left. Ready on the right. Ready on the firing line. Cannon discharge in three. Two. One. ZERO. BOOM !
-- 10 kg ball flying THAT way ==> at 200 m/s.
Momentum= (10kg)x(200 m/s THAT==>way = 2,000 kg-m/s THAT==>way
-- Cannon momentum = (1000 kg) x (velocity THIS <== way)
Cannon momentum = 2,000 kg-m/s THIS<==way
(1000 kg) x (velocity) = 2,000 kg-m/s this<==way
Divide each side by (1,000 kg):
Velocity = (2,000 kg-m/s) / (1,000 kg) this<==way
Velocity of the cannon = 2 m/s this<==way
Which would BEST describes what occurs when a ball is thrown against a wall?
A) The ball will not bounce off the wall.
B) The ball hits the wall hard enough to bounce off of it.
C) The wall is stronger than the ball and neither exerts any forces.
D) The ball exerts a force on the wall and the wall exerts a force back.
When a ball is thrown against a wall, the ball exerts a force on the wall, and the wall exerts an equal force in the opposite direction back on the ball. (D)
Answer:
The ball exerts a force on the wall and the wall exerts a force back.
Explanation:
When a ball is thrown against a wall, the ball exerts a force on the wall and the wall exerts a force back. This is due to Newton's third law of motion. According to this law, every action have equal and opposite reaction and both action and reaction forces acts on different object.
In this case, when a ball is thrown against a wall, the wall exerts an equal force on the the ball but in opposite direction. It follows the newton's third law.
Hence, the correct option is (D).
in a transfer of energy, there is no change in the energy's, what?
I think it is there is no change in the energy's sunlight
Which type of cloud is tall and associated with thunderstorms
Cumulonimbus clouds will be your answer. They are both tall and associated with thunderstorms. Hope I helped!
If a rock is dropped with a weight of 50kg and friction due to air resistance produces a force of 98N, what is the net force in the Y direction?
PLEASE HELP 11 POINTS
Answer:
The net force is 392N, pointing down.
Explanation:
The net force is the sum of all forces acting on the rock, namely the gravity ("+" acting downward) and the friction force due to air resistance ("-" acting upward):
[tex]F_{net} = F_g - F_{air}\\F_{net} = m\cdot g - F_{air} = 50kg\cdot 9.8\frac{m}{s^2}-98N= (490-98)N=392N[/tex]
The net force is 392N and pointing down (positive)/
A dog weighs 260 Newtons. What is her mass?
260 Newtons equals 26.51 Kg, or 58.44 lbs.
Hope this helps!
An object with more mass has more kinetic energy than an object with less mass, if both objects are moving ____.
Select one:
a. in the same direction
b. in the opposite direction
c. at the same speed
An object with more mass has more kinetic energy than an object with less mass, if both objects are moving at the same speed. (c)
Answer:
c. at the same speed
Explanation:
How does a mathematical model help you understand the science concepts? Give an example.
A mathematical model helps us understand science concepts by providing a simplified representation of complex phenomena.
Explanation:A mathematical model helps us understand science concepts by providing a simplified representation of complex phenomena. It allows us to analyze and predict the behavior of the real system without directly studying it. For example, the kinetic molecular theory of gases is a mathematical model that helps us understand the behavior of gases by describing them as collections of moving particles.
Which describes a train’s acceleration if it changes speed from 25 m/s to 10 m/s in 240 s? positive acceleration no acceleration negative acceleration
To understand acceleration, you need to know speed and velocity.
Why?
Acceleration is the change in velocity, and the velocity equation is:
velocity = distance / time Units: (m/s)
If a change in position means an object has a velocity, then that means that a change in velocity has an acceleration (I recommend you look at the graphs, it will help a lot to understand the relationship between each).
Now that we have some background, lets use it to answer the problem!
The change in velocity is from 25 m/s to 10 m/s, and we have a time. Lets plug it into the (average) acceleration equation so we can visualize it better!
The symbol delta means "change" : Δ
a = Δv / Δt
expanded to:
a = vf - vi / tf - ti
(vf = velocity final, vi = velocity initial, tf = time final, ti = time initial)
So if the train's speed went from 25 m/s to 10 m/s, then that means that 10 m/s is our final velocity and 25 m/s is the initial:
a = 10 - 25 / 240
a = -15 / 240
a = -0.0625 m/s^2
Since we ended up with a negative number, it means that the train has a negative acceleration!!!!!
The fast way to do this:
25 m/s is bigger than 10 m/s, so that means that to go from 25 m/s to 10 m/s you have to slow down--otherwise known as putting on your brakes. So if the change in speed is negative then the acceleration will be negative.
In other words, if your final speed is less than your initial speed then your acceleration would be negative.
Sorry for the long explanation! I hope you never struggle with this again though!
Hope it helped,
Answer: negative acceleration
Explanation:
If the bond enthalpy for a C-H bond is 413 kJ, what will happen when the C-H bond is broken?
Explanation:
Bond Enthalpy : It is defined as amount of energy required to break a the particular bond in there gaseous state. It is also known as bond energy. It units are kJ/mol.
Breaking of a bond is an Endothermic process (energy absorbed from the surroundings).Formation of bond is an Exothermic process (energy is released to the surroundings).If the average bond enthalpy for a C-H bond is 413 kJ/mol, When the C-H bond breaks in which energy will be required ,which will be an endothermic reaction.
A car travels at 84 kilometers per hour for 7 hours. How far did it travel?
The difference between an innate behavior and a learned behavior is that a learned behavior is __________ and an innate behavior is not.
A.
based on inborn responses
B.
instinctive
C.
based on reflexes
D.
a result of experience
Answer:
D. a result of experience
Explanation:
on edge
An object moving at a constant speed in a circle is _____.
A. accelerating
B. changing its speed
C. not changing its velocity
D. not changing its direction
Please help me idek if this is physics
Answer:
A. accelerating
Explanation:
Acceleration is defined as the ratio between the change in velocity and the time taken for the velocity to change:
[tex]a=\frac{\Delta v}{\Delta t}[/tex]
We must note that the velocity is a vector - so it has both a magnitude (the speed) and a direction.
This means that a non-zero acceleration occurs when:
- the speed changes, or
- the direction changes, or
- both the speed and the direction change
For an object moving at constant speed in a circle, the direction changes, so the object is accelerating.