Answer:
According to newton's first law of motion, friction is required to make an object slow down.
Explanation:
According to the Newton's first law of motion, for an object to change its velocity (either a change in the magnitude or the direction), there must be a cause to it which is defined as a net external force.
For example, an object which is sliding across a table or floor slows down due to the net force of friction that is acting on that object.
At what point on the hill with the car have zero gravitational potential energy
A) halfway down the hill
B) at the top of the hill
C)at the bottom of the hill
D) it will never have zero gravitational potential energy
Gravitational potential energy of the car is given by formula
[tex]U = mgh[/tex]
here m = mass of the car
g = gravitational field intensity
h = height of the car from reference point
so here from above formula we can say that if height of the car from reference is zero the gravitational potential energy will be zero
So here we generally took the reference point to be at bottom on the ground
so here also the gravitational potential energy will be zero at the ground
so correct answer will be
C)at the bottom of the hill
Answer:
C) up a hill and then rolling back down the other side.
Explanation:
a truck drives up a hill with a 15 incline. if the truck has a constant speed of 22m/s, what are the horizontal and vertical components of the trucks velocity
Answer:
speed of truck (v) = 22 m/s ,
angle of hill (Θ) =15°
Find
Vertical component (Fv) = ?
Harizontal component (Fh) =?
Vertical component (Fh) = V cosΘ
= 22. cos 15
= 21.25 m/s.
Harizontal component (Fv) = V sinΘ
= 22. sin 15
= 5.69 m/s.
a. The horizontal component of the truck's velocity is 5.69 m/s.
b. The vertical component of the truck's velocity is 21.25 m/s.
Given the following data:
Angle of inclination = 15°Velocity of truck= 22 m/sTo find both the horizontal and vertical components of the truck's velocity:
a. To find the horizontal component of the truck's velocity:
Mathematically, the horizontal component of velocity is given by the formula:
[tex]V_y = Vsin(\theta)\\\\V_y = 22sin(15)\\\\V_y = 22 \times 0.2588[/tex]
Horizontal component, Vy = 5.69 m/s
b. To find the vertical component of the truck's velocity:
Mathematically, the vertical component of velocity is given by the formula:
[tex]V_x = Vcos(\theta)\\\\V_x = 22sin(15)\\\\V_x = 22 \times 0.9659[/tex]
Vertical component, Vx = 21.25 m/s
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Which of the following factors determines the strength of the frictional force between two surfaces?
The amount of heat generated by the frictional
The types of surfaces involved
The objects' sizes
How hard the surfaces push together
Answer:
option 2 and 4
Explanation:
The strength of frictional force depends on the types of forces involved and how hard the surfaces push together.
If the surfaces are rough, then the frictional force between two surfaces is more and if the surfaces are smooth, the frictional force between two surfaces is less.
If they push hard, it means the weight on the surface is more and thus, the normal reaction force is more.
Friction force is directly proportional to the normal reaction force, so, the friction force depends on the push.
28) Q: A: You are sitting in a car that isn't moving; suddenly, the car quickly accelerates. Your body seems to be pushed back against the seat. Which word best explains why your body seemed to be pushed backward against the seat?
the seat is moving with the car and pushing you to keep up with the car or else the seat breaks and you go flying backwards until something stops you .... ouch.
You feel pushed back against the seat, but it's the seat pushing you forward.
Answer:
Inertia.
Explanation:
The first law of Newton states that a body will remain in the same state of motion ( relative rest or uniform movement) if there is no force applied to it.
Why will the body remain in the same state of motion? This is because of inertia.
Inertia is the property of bodies that tries to keep them in a state of motion.
In the case that the car suddenly moves, your inertia tries to keep you in a relative rest to the ground, that's why your body feels like being pushed back.
Which of the following types of stars is most likely to end up as a red supergiant?
A
B
C
D
Answer:
Option D
Explanation:
Red Super giants are the biggest stars in our universe and are formed when the inner core of a star does not have its fuel which is hydrogen. The outer layer starts to do fission and thus become very hot.
As per the given graph, the wavelength is increasing in option D thus radiating more energy and heat. Wavelength of red color lies in range given in last graph.
A boat takes 3.0 hours to travel 50 km down a river, then 5.4 hours to return. Determine the speed of the water in the river.
Answer:
3.7 km/h
Explanation:
Let's call v the proper speed of the boat and v' the speed of the water in the river.
When the boat travels in the direction of the current, the speed of the boat is:
v + v'
And it covers 50 km in 3 h, so we can write
[tex]v+v' = \frac{50 km}{3 h}=16.7 km/h[/tex] (1)
When the boat travels in the opposite direction, the speed of the boat is
v - v'
And it covers 50 km in 5.4 h, so
[tex]v-v'=\frac{50 km}{5.4 h}=9.3 km/h[/tex] (2)
So we have a system of two equations: by solving them simultaneously, we find the value of v and v':
[tex]v+v'=16.7 \\v-v'=9.3[/tex]
Subtracting the second equation from the first one we get:
[tex](v+v')-(v-v')=16.7-9.3\\2v'=7.4\\v'=3.7[/tex]
So, the speed of the water is 3.7 km/h.
An Aluminium bar is 3.25m long and has a diameter of 25mm. If the temperature difference between the ends is 250°C, find the rate of heat transfer along the bar. (Where the Thermal conductivity for Al is 205W/m°C)
is it 5.67 W, 7.74 W, or 10.5 W?
Answer
7.74 W
Explanation
The formula for getting the the rate of heat transfer is:
[tex]\frac{Q}{T}[/tex]=[tex]\frac{KA(T2 - T1) }{d}[/tex]
A = πr² = π×(12.5/1000)²
= 4.908×10⁻⁴m²
Rate of heat transfer = [tex]\frac{205*4.908×10⁻⁴*250}{3.25}[/tex]
= 7.74 W
A person standing at the edge of a merry-go-round must hold on tightly to keep from flying off the edge as it speeds up. What name is given to the force that keeps the person moving in a circular path?
Answer:
The force in this setting is called centripetal.
Explanation:
While the centripetal force acts in the direction pointing toward the center of the curvature (in this case the center of the merry-go-around), the foce opposing it is referred to as centrifugal.
Answer:
Centripetal force
Explanation:
If a bicyclist is traveling 60 kilometers in two hours her average speed is?
Her average speed would be 30 kilometers in a hour.
Answer: Her average speed would be 30 kilometers per hour because 60 divided by two is 30 which is how you can calculate the average speed if desired.
Hope this helps! :)
Explanation:
How are analog and digital signals similar? Check all that apply.
Both reduce noise.
Both pick up noise. Both make noise louder.
Both transmit data or information.
Both get weaker when traveling long distances.
Answer:
Both transmit data or information.
Both get weaker when traveling long distances.
Answer:
Both transmit data or information.
Both get weaker when traveling long distances.
Explanation:
Just did it on Ed. ^^
In the diagram, the center dot represents the car, and the arrows represent the forces acting on the car Which term describes the forces acting on the car. A- inertial B- buoyant. C- unbalanced. D- balanced
Answer:
C- unbalanced
Explanation:
The arrow to the right has 1000 N less than the rest of the other forces, this means that the forces are unbalanced and the object is moving left.
The sum of the forces along the horizontal component is not equal to that of the vertical, hence the force acting on the car is an unbalanced force
From the given diagram, we have forces acting in the x and y-direction. In order to determine the nature of the forces acting on the car, we will take the sum of the forces acting on the car as shown:
For the horizontal component;
[tex]\sum F_x =+5000 - 6000\\\sum F_x = -1000N[/tex]
Similarly for the vertical component;
[tex]\sum F_y = 6000 - 6000\\\sum F_y = 0N[/tex]
Since the sum of the forces along the horizontal component is not equal to that of the vertical, hence the force acting on the car is an unbalanced force
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Which could cause a satellite to descend low enough that it burns up in the Earths atmosphere?
A. Centripetal force
B. Air resistance
C. Gravitational force
Answer:
B. Air resistance
Explanation:
If the distance at which the satellite orbits is not enough to avoid the atmospheric drag, it will be affected by the friction of the Earth's atmosphere and the drag will slow down the speed of the satellite. Therefore, It will result in the reduction in the altitude of a satellite's orbit and eventually burn.
What are two places in your body where you find smooth muscles
Some places where you can find smooth muscles in your body are,
the walls of your blood vessels,
the walls of your stomach,
the intestines,
and the iris of your eye.
those are just some.
if you need different ones, I have more.
hope i could help!what force is required to accelerate a 10 kg mass at 5m/sec^2
Given Data
Acceleration (a) = 5 m/s²
mass ( m) = 5 Kg
From Newtons II law, We know that
F = m. a
F = 10 × 5
= 50 N
50 N force is required to accerate the mass
A pendulum swings back and forth and has a kinetic energy of 400 j at a particular point in its path. Which of the following is not true
A- both the kinetic and potential energy are decreasing
B- the minimum kinetic energy is zero
C- when the kinetic energy is zero, the potential energy will be 400 J
D- the potential energy increases when the kinetic energy decreases
A pendulum swings performing back and forth motion and having a kinetic energy of 400 J then both the kinetic and potential energy are decreasing. Hence, option A is correct.
What is Kinetic energy?The energy that an object has as a function of motion is known as kinetic energy. It is described as the effort required to move a surplus body from rest to the indicated velocity. The body will hold onto the kinetic energy it acquired during its acceleration until its speed changes.
The body exerts the same amount of effort when slowing from its current pace to a condition at rest. Formally, angular momentum is any term in the Lagrangian of a system having a time derivative. Mathematically, it is represented as [tex]\frac{1}{2} mv^2[/tex].
Therefore, both the kinetic and potential energy is decreasing, so option A is correct.
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Final answer:
The statement that is not true is 'both the kinetic and potential energy are decreasing,' as this violates the conservation of energy in a swinging pendulum. Energy is transferred from potential to kinetic and vice versa, not decreased simultaneously.
Explanation:
The question relates to the conservation of energy in a swinging pendulum, a common topic in high school physics. Specifically, it concerns the relationship between kinetic energy and potential energy during the pendulum's motion.
When a pendulum swings back and forth, its kinetic energy and potential energy are constantly interchanged. At the highest points of the swing, where the pendulum momentarily stops before changing direction, the kinetic energy is zero and all energy is stored as potential energy. On the other hand, at the lowest point in its path, where the pendulum moves fastest, the potential energy is at its minimum and kinetic energy is at its maximum.
Given this information, let us examine the provided statements:
A- This statement is incorrect because, at a particular point, both energies cannot be decreasing at the same time since energy is being transferred from one form to the other.
B- This is true, as the kinetic energy is zero when the pendulum reaches its highest point.
C- When the pendulum's kinetic energy is zero at its highest point, the potential energy equals the total mechanical energy, which would be 400 J if no energy were lost to friction or air resistance.
D- This statement is correct as it follows the principle of energy conversion, where an increase in potential energy is matched by a corresponding decrease in kinetic energy and vice versa.
Therefore, the statement that is not true is A - both the kinetic and potential energy are decreasing. The potential energy increases when the pendulum reaches the highest points of its swing (where the kinetic energy decreases to zero), and the kinetic energy increases as the pendulum swings downward and potential energy decreases.
Amy has a mass of 30 kg, and she is riding a scateboard traveling 5 m/s. what is her momentum?
Answer:
Momentum (p) = m . v Kg-m/s
= 30 × 5
p = 150 Kg .m/s
Which of the following is an example of acceleration? Select one: a. A boy walks two miles in one hour. b. A girl walks two miles per hour north for three hours. c. A boy walks two meters north, turns west, and walks another two meters. d. A girl drives a total distance of 240 miles in just under four hours.
The answer is option C .Because as the direction of the boy changes ;velocity changes .
Answer
Correct answer is option C .
Explanation:
Option A cannot be correct option because in this case only distance traveled and time is given we are not sure whether velocity is changing or not.
Option B
In this case girl travel with constant velocity so it cannot be accelerated motion
Option C
Correct option is C. Because as the direction of the boy changes that time velocity changes and rate of change of velocity with respect to time is known as acceleration
Option D
In this case also only distance and time is given we cant say whether it is accelerated motion or not
Astronauts often undergo special training in which they are subjected to extremely high centripetal accelerations. One device has a radius of 15 m and can accelerate a person at 98 m/s2. What is the speed of the astronaut in this device?
Answer:
Speed of astronaut = 38.34 m/s
Explanation:
Centripetal acceleration is given by the expression, [tex]a=\frac{v^2}{r}[/tex], where v is the velocity and r is the radius.
Here centripetal acceleration is given, radius is given, we need to find velocity.
Centripetal acceleration = 98 m/s²
Radius = 15 m.
We have,
[tex]a=\frac{v^2}{r} \\ \\ 98=\frac{v^2}{15} \\ \\ v=38.34m/s[/tex]
Speed of astronaut = 38.34 m/s
If Steve throws the football 50 mentees in 3 seconds what is the average speed (velocity) of the football
(50 meters) / (3 seconds) = (50/3) (meters/sec) = (16 and 2/3) meters/sec .
Speed is correct.
It's NOT velocity.
They're different things.
The two waves shown here are the same distance from point x and are traveling toward each other
What is the amplitude of the resulting wave when the two waves meet at point x
A). 0.0 cm
B) 1.0 cm
C) 2.0 cm
D) 4.0 cm
The Answer should be A: 0.0
Answer:
A). 0.0 cm
Explanation:
When two waves travel and meet at the same point, a phenomenon known as interference occurs.
The two extreme cases of interference are the following:
- When two waves in phase meet at the same point, the resultant wave produced by the interference has amplitude which is the sum of the amplitude of the individual waves
- When two waves in anti-phase meet at the same point, the resultant wave produced by the interference has amplitude which is the difference between the amplitudes of the individual waves
In this problem, we have two waves of amplitde A1 = 2.0 cm and A2 = 2.0 cm that meet at X in anti-phase (because they have opposite displacement): therefore, it is a destructive interference, and the resultant amplitude will be
[tex]A=A_1 -A_2 = 2.0 cm - 2.0 cm = 0.0 cm[/tex]
A ____________ is a machine which contains a lever and a wedge that combine to make work easier.
Answer: Simple machine
The movable inclined plane is called wedge.A simple machine is a machine, which contains lever and wedge, is used to push the things apart. The mechanical advantage of a wedge is given by the ratio of length of its slope to its width.Someone who appears to be lacking in intelligence according to intelligence testing scores but seems to excel in other domains is said to have
Someone who appears to be lacking in intelligence according to intelligence testing scores but seems to excel in other domains is said to have SAVANT SYNDROME
Answer:
Someone who appears to be lacking in intelligence according to intelligence testing scores but seems to excel in other domains is said to have SAVANT SYNDROME
Explanation:
Savant Syndrome is a set of anomalous cognitive symptoms where people suffer from a major left hemisphere disability; however, they can perform surprisingly well some tasks that involve the right hemisphere. People with savant syndrome develop talents, that is, extraordinary abilities in particular, concrete and peculiar.
In other words, according to this syndrome, some people with mental disorders and despite their physical, mental or motor disabilities, possess a surprising ability or specific mental abilities. That is, it is a condition in which a person with a mental disorder (such as an autism spectrum disorder) demonstrates a deep and prodigious ability or ability, far superior to what would be considered normal.
People with Savant Syndrome may have neurodevelopmental disorders (especially autism spectrum disorders) or brain injuries.
The most common abilities of the Savant are centered in Art (music, painting and sculpture), Calculation of dates, Mathematical calculation and mechanical and spatial skills.
a ramp with a mechanical advantage of 8 lifts objects to a height of 1.5 meters how long is the ramp
Given data:
M.A. = 8 (No units),
Ramp height (h)= 1.5 m, lifted,
Determine how long is the ramp=?
General formula
Mechanical Advantage = (Ramp length) ÷ (Ramp height),
M.A = l ÷ h
8 × 1.5 = l = 12 m long
length of the ramp l ramp = 12 m
The length of the ramp can be found using the mechanical advantage formula. Given a mechanical advantage of 8 and a height of [tex]1.5 m[/tex], the ramp length is [tex]12 m[/tex].
Determining the Length of the Ramp
To determine the length of the ramp, we can use the formula for mechanical advantage (MA) of an inclined plane, which is given by:
MA = Length of ramp / Height of ramp
From the question, we know the mechanical advantage (MA) is 8, and the height of the ramp is 1.5 meters. Let's use the formula to find the length of the ramp:
[tex]8 = \text{Length of ramp} / 1.5[/tex]
[tex]\text{Length of ramp} = 8 \times 1.5 = 12 m[/tex]
Therefore, the ramp is 12 meters long.
(Tennis)
Match the terms to their definition.
A ) ace
a stroke done to the right-front of the body (for right-handers), with the racket in a normal position (palm of hand facing opponent)
B ) backhand stroke
position facing the net. Used to begin most tennis strokes
C ) endurance
a tennis stroke made across the body with the back of the hand facing the direction of the stroke
D ) fault
exercising to increase stamina; mostly associated with aerobic activities and cardiovascular health
E ) flexibility
the way the game begins. Governed by a specific set of rules
F ) forehand stroke
a tennis stroke that creates a backspin on the ball
G ) let
is the absolute range of movement in a joint or series of joints and muscles
H ) rally
forward spin (usually of a moving ball) that is imparted by an upward stroke
I ) ready position
a sequence of shots within a point
J ) service
to exert force on an object using muscles
K ) slice
a service winner; the opponent cannot return the serve
L ) strength
when the service hits the net and lands in a let is played and the server gets another ball
M ) topspin
when the ball does not land in the service box
Help me with theses 2 questions please.
1. Describe a situation in which an object gains the same amount of GPE(gravitational potential energy) when two different paths are taken to the same point. Explain (using requirements of work) why this is.
2. Explain what equilibrium and spring constant mean in relation to elastic potential energy.
Thanks if you can help with this.
1)
Answer: A inclined plane and staircase reaching the same height. Work depends on initial and final position only.
Explanation:
The amount of work done does not depend on path length. It depends on initial and final position. It is given by gravitational potential energy.
W = m g h
Where, m is the mass of the object, g is the acceleration due to gravity and h is the height.
Let the mass of the object be m. Two different paths ( one inclines plane and another staircase) are taken to same point. The object would gain same gravitational potential energy because it depends on the height through which the object is taken and not the actual path length.
W ∝ h.
2)
Spring constant can be defined as the ratio of amount of force acting spring with the displacement caused due to the force. A deformed elastic object has elastic potential energy stored in it which is equal to the work done to deform the object. It is proportional to the spring constant and amount of stretched distance.
Equilibrium is reached when the net force acting on the spring is zero. In equilibrium state, the object has natural extension. An object is said to possess elastic potential energy when force is applied and object deforms relative to original equilibrium shape or length.
Compare solids, liquids, and gases in terms of their shape and volumes.
Help with the two questions above? Correct answers?
(6) first choice: the frequency appears higher and wavelength is shorter.
The car approaches a stationary observer and so the sound will appear to have shorter wavelength. This creates an effect of its siren to sound with higher frequency than it would do if both were stationary.
(7) The Doppler formula for frequency in the case of a stationary observer and source approaching it is as follows:
[tex]f_O = \frac{v}{v-v_s}\cdot f= \frac{343\frac{m}{s}}{(343-25)\frac{m}{s}}\cdot 400Hz \approx 431Hz[/tex]
The wavelength is then
[tex]\lambda = \frac{343\frac{m}{s}}{431Hz}\approx 0.80 m[/tex]
The third choice "0.80m; 431Hz" is correct
Which layer in the atmosphere contains the most water vapor and gases? A. thermosphere B. stratosphere C. mesosphere D. troposphere
D. Troposphere
The layer of the atmosphere that is above the troposphere and in which temperature increases as altitude increases. This atmospheric layer contains the ozone layer. The layer closest to Earth, where almost all weather occurs. It contains the gases water vapor, oxygen, nitrogen, and carbon dioxide.
Troposphere layer in the atmosphere contains the most water vapor and gases. Hence, option (D) is correct.
What is atmosphere?The atmosphere is a key component of Earth's interconnected physical systems. The layers of gases that surround a planet or other celestial body form the atmosphere.
The Earth's atmosphere is made up of 78% nitrogen, 21% oxygen, and 1% other gases. These gases are found in the atmospheric layers (troposphere, stratosphere, mesosphere, thermosphere, and exosphere), which are distinguished by distinct characteristics such as temperature and pressure.
The atmosphere shields life on Earth from incoming ultraviolet (UV) radiation, keeps the planet warm through insulation, and prevents temperature extremes between day and night. The sun heats the layers of the atmosphere, causing convection, which drives air movement and weather patterns all over the world.
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Which of the following is NOT a recommended change in physical activity for aging individuals? A. taking a longer time to warm up and cool down B. being cautious about exercising in extreme conditions C. using less weight, but adding repetitions D. participating only in cardiovascular exercises Please select the best answer from the choices provided. A B C D
participating only in cardiovascular exercises
Participating only in cardiovascular exercises is not a recommended change in physical activity for aging individuals.
What is Cardiovascular exercise?This is the type of physical activity which stresses the cardiorespiratory system.
It is however not ideal for aging individuals due to their weak body system which is why option D was chosen.
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A car is pulled with a force of 10,000 N. The car's mass is 1267 kg. But, the car covers 394.6 m in 15 seconds
[a]What is the expected acceleration of the car from 10,000 N force?
[b]What is the actual acceleration from the observed data of x and t?
[c]What is the difference in accelerations?
[d]What force caused this difference?
[e]What is the magnitude and direction of the force that caused the difference in acceleration?
F=m*a=>a=F/m=10000/1267=7.89 m/s²
d=v₀t+a't²/2<=>394.6=112.5*a'=>a'=3.5
a-a'=7.89-3.5=4.39 m/s²
This difference causes friction forces
We apply the second principle of dynamics: vector: F + N + G + Ff = ma (vector vectors, I can not here)
Scalar: Ox: F-Ff = ma
Oy N-mg = 0
Ff = -ma+ F =-1267*7.89+10000=-8869+10000=1131 N
This frictional force (Ff) is opposite to the traction (F)