question

distance / kinetic

answer

The work-energy theorem states that a force acting on a particle as it moves over a ______ changes the ______ energy of the particle if the force has a component parallel to the motion.
Choose the best answer to fill in the blanks above:
distance / potential
distance / kinetic
vertical displacement / potential
none of the above

question

distance

answer

To calculate the change in energy, you must know the force as a function of _______. The work done by the force causes the energy change.
Choose the best answer to fill in the blank above:
acceleration
work
distance
potential energy

question

force / kinetic

answer

To illustrate the work-energy concept, consider the case of a stone falling from xi to xf under the influence of gravity.
Using the work-energy concept, we say that work is done by the gravitational _____, resulting in an increase of the ______ energy of the stone.
Choose the best answer to fill in the blanks above:
force / kinetic
potential energy / potential
force / potential
potential energy / kinetic

question

change / potential

answer

Rather than ascribing the increased kinetic energy of the stone to the work of gravity, we now (when using potential energy rather than work-energy) say that the increased kinetic energy comes from the ______ of the _______ energy.
Choose the best answer to fill in the blanks above:
work / potential
force / kinetic
change / potential

question

sum / conserved

answer

his process happens in such a way that total mechanical energy, equal to the ______ of the kinetic and potential energies, is _______.
Choose the best answer to fill in the blanks above:
sum / conserved
sum / zero
sum / not conserved
difference / conserved

question

Wd = 1/2mv^2?mgd

answer

What is the work Wd done on the skydiver, over the distance d, by the drag force of the air?
Express the work in terms of d, v, m, and the magnitude of the acceleration due to gravity g.

question

Pd = -mgv

answer

Find the power Pd supplied by the drag force after the skydiver has reached terminal velocity v.
Express the power in terms of quantities given in the problem introduction.

question

d = mg/k+L

answer

How far below the bridge will Kate eventually be hanging, once she stops oscillating and comes finally to rest? Assume that she doesn't touch the water.
Express the distance in terms of quantities given in the problem introduction.

question

k = 2mgh(h?L)2

answer

If Kate just touches the surface of the river on her first downward trip (i.e., before the first bounce), what is the spring constant k? Ignore all dissipative forces.
Express k in terms of L, h, m, and g.

question

at its maximum value at the lowest point of the track.

answer

Where on the track is the skater's kinetic energy the greatest?
The skater's kinetic energy is
at its maximum value at the lowest point of the track.
the same everywhere.
at its maximum value at the locations where the skater turns and goes back in the opposite direction.

question

at its maximum value at the locations where the skater turns and goes back in the opposite direction.

answer

Change the Energy vs. Position graph to display only potential energy.
As the skater is skating back and forth, where does the skater have the most potential energy?
The skater's potential energy is
at its maximum value at the locations where the skater turns and goes back in the opposite direction.
at its maximum value at the lowest point of the track.
the same everywhere.

question

the same at all locations of the track.

answer

Display the total energy in the Energy vs. Position graph. As the skater is skating back and forth, which statement best describes the total energy?
The total energy is
smallest at the locations where the skater turns to go back in the opposite direction and greatest at the lowest point of the track.
the same at all locations of the track.
greatest at the locations where the skater turns and goes back in the opposite direction and smallest at the lowest point of the track.

question

equal to the amount of potential energy loss in going from the initial location to the bottom

answer

Based on the previous question, which statement is true?
The kinetic energy at the bottom of the ramp is
equal to the initial potential energy.
equal to the amount of potential energy loss in going from the initial location to the bottom.
equal to the total energy.

question

2205 J

answer

If the skater started from rest 4 m above the ground (instead of 7m), what would be the kinetic energy at the bottom of the ramp (which is still 1 m above the ground)?
2205 J
4410 J
2940 J
735 J

question

11 m/s

answer

Tne common application of conservation of energy in mechanics is to determine the speed of an object. Although the simulation doesn't give the skater's speed, you can calculate it because the skater's kinetic energy is known at any location on the track.
Consider again the case where the skater starts 7 m above the ground and skates down the track. What is the skater's speed when the skater is at the bottom of the track?

question

higher, but less than twice as fast.

answer

When the skater starts 7 m above the ground, how does the speed of the skater at the bottom of the track compare to the speed of the skater at the bottom when the skater starts 4 m above the ground?
The speed is
the same.
higher, but less than twice as fast.
twice as fast.
four times as fast.

question

equal to zero.

answer

Change the potential energy reference line to be 7 m above the ground (select the Potential Energy Reference option, and click and drag on the dashed blue horizontal line to the 7 m grid line). Place the skater on the track 7 m above the ground, and let the skater go.
The total energy of the skater is
greater than zero.
less than zero.
equal to zero.

question

the same as the case when the potential energy reference was the ground.

answer

At the bottom of the hill, how does the kinetic energy compare to the case when the potential energy reference was the ground and the skater was released 7m above the ground?
The kinetic energy is
the same as the case when the potential energy reference was the ground.
greater than the case when the potential energy reference was the ground.
less than the case when the potential energy reference was the ground.

question

directed to the left

answer

The force acting on the particle at point A is __________.
directed to the right
directed to the left
equal to zero

question

directed to the right

answer

The force acting on the particle at point C is __________.
directed to the right
directed to the left
equal to zero

question

equal to zero

answer

The force acting on the particle at point B is __________.
directed to the right
directed to the left
equal to zero

question

equal to zero

answer

The acceleration of the particle at point B is __________.
directed to the right
directed to the left
equal to zero

question

directed to the left

answer

If the particle is located slightly to the left of point B, its acceleration is __________.
directed to the right
directed to the left
equal to zero

question

directed to the right

answer

f the particle is located slightly to the right of point B, its acceleration is __________.
directed to the right
directed to the left
equal to zero

question

B,F

answer

Name all labeled points on the graph corresponding to unstable equilibrium.

question

D, H

answer

Name all labeled points on the graph corresponding to stable equilibrium

question

B,D,F,H

answer

Name all labeled points on the graph where the acceleration of the particle is zero.

question

A, E

answer

Name all labeled points such that when a particle is released from rest there, it would accelerate to the left.

question

A

answer

Consider points A, E, and G. Of these three points, which one corresponds to the greatest magnitude of acceleration of the particle?
A
E
G

question

D

answer

What point on the graph corresponds to the maximum kinetic energy of the moving particle?

question

B

answer

At what point on the graph does the particle have the lowest speed?