At what point in its fall
does the KE of a freely falling object equal its PE ? at the
start of the fall halfway
between the start and the end
at
the end of the fall at all
points during the fall 2.
A crate is pulled 6.0 m up an
incline with a force of 50 N. If the PE of the crate increases 250 J, the total work done against
friction in moving the box is 0 J
50 J
250 J
300 J
3.
If the KE of a given mass is
to be doubled, its speed must be multiplied by 8 2 square
root of 2 4 4.
If the velocity of an
automobile is doubled, its KE decreases
to one-half doubles
decreases
to one-fourth quadruples
5.
A weightlifter lifts a 2000 N
weight a vertical distance of 0.5 m in 0.1 s. What is the power output ? 0.0001
W 0.0004
W 10,000 W
40,000
W 6.
As an object slides down a
frictionless incline, the sum of the gravitational PE and the KE of the object will decrease
increase
remain
the same 7.
The work done on a 10.0 kg
mass to give it a speed of 5.00 m/s is 50.0 J
2.00 J
125 J
250. J
8.
A 20 kg mass moving at a speed
of 3.0 m/s is stopped by a constant force of 15 N. How many seconds must the force act on the
mass to stop it ? 0.20 s
1.3 s
5.0 s
4.0 s
9.
A 2.0 kg mass falls freely for
10. m near the surface of the Earth. The total KE gained by the object during its free-fall is
approximately 400 J
200 J
100 J
50 J
10.
A net force of 12 N acting
north on an object for 4.0 s will produce an impulse of 48
kg*m/s north 48
kg*m/s south 3.0
kg*m/s north 3.0
kg*m/s south 11.
What is the spring constant
of a spring of negligible mass which gained 8 J of potential energy as a result of being compressed 0.4 m ? 100 N/m 50 N/m 0.3
N/m 40 N/m 12.
The work done in raising an
object must result in an increase in the object’s internal
energy kinetic
energy gravitational
PE elastic
PE 13.
Which term is a unit of power
? Joule Newton Watt Newton*meter 14.
A rocket with a mass of 1000
kg is moving at a speed of 20 m/s. The magnitude of the momentum is 50
kg*m/s 200
kg*m/s 20,000
kg*m/s 400,000
kg*m/s 15.
An unbalanced force of 6.0 N
acts eastward on an object for 3.0 s. The impulse produced by the force is 18 N*s
east 2.0
N*s east 18 N*s
west 2.0
N*s west 16.
What is the magnitude of the
velocity of a 25 kg mass that is moving with a momentum of 100 kg*m/s ? 0.25
m/s 2500
m/s 40.
m/s 4.0 m/s 17.
What is the maximum distance
that a 60 W motor may vertically lift a 90 N weight in 7.5 s ? 2.3 m 5.0 m 140 m 1100 m 18.
Two objects unequal in mass
falling freely from the same point above the earth’s surface will experience the same
acceleration decrease
in PE increase
in KE increase
in momentum 19.
A 20 kg object is moved a
distance of 6.0 m by a net force of 50 N. The total work done is 120 J 300 J 420 J 1000 J 20.
A 2 kg object is thrown
vertically upward with an initial KE of 400 J. The object will rise to a height of
approximately 10 m 20 m 400 m 800 m 21.
Which is a scalar quantity ? acceleration momentum force energy 22.
A simple pendulum whose mass
is 1.00 kg swings to a maximum height of 0.200 m above its lowest point. Neglecting friction, the KE of
the pendulum bob at the lowest point in its swing is 0.980
J 1.96 J 9.80 J 19.6 J 23.
A bullet fired from a rifle
emerges with a KE of 2400 J. Neglecting friction, if the barrel of the rifle is 0.50 m long, the average force on
the bullet in the barrel is approximately 600 N 1200 N 2400 N 4800 N 24.
Which is a vector quantity ? power weight energy mass 25.
If an object weighing 1.00 N
falls a vertical distance of 4.00 m, the object’s loss in gravitational PE is 1.00 J 9.80 J 39.2 J 4.00 J 26.
A 2 N force acts on an
object. If the momentum of the object changes by 120 kg*m/s, the force must have acted for
8 s 30 s 60 s 120 s 27.
A 20. N block falls from a
shelf 3.0 m above the ground. Its KE at 1.5 m above the ground is 20. J 30. J 60. J 120 J 28.
If the KE of a 10. kg mass is
80 J, its speed is 1 m/s 0.125
m/s 8 m/s 4 m/s 29.
A force of 70 N must be
exerted to keep a car moving with a constant speed of 10 m/s. What is the rate at which energy must be supplied ? 0.14 W 7.0 W 700 W 7000 W 30.
A 2 kg mass moving along a
horizontal surface at 10 m/s is acted upon by a 5 N force of friction. The time required to bring the mass to rest is 10 s 2 s 5 s 4 s 31.
Two carts of masses 5.0 kg and
1.0 kg are pushed apart by a compressed spring. If the 5.0 kg cart moves westward at 2.0 m/s,
the magnitude of the velocity of the 1.0 kg cart will be 2.0
kg*m/s 2.0
m/s 10.
kg*m/s 10. m/s
32.
Two carts resting on a
frictionless surface are forced apart by a spring. One cart has a mass of 2 kg and moves to the left at
3.0 m/s. If the second cart has a mass of 3 kg, it will move the right with a speed of 1 m/s
2 m/s
3 m/s
6 m/s
33.
An 80. kg skater and a 60. kg
skater stand at rest in the center of a skating rink. The two skaters push each other apart.
The 60. kg skater moves east at 10 m/s. What is the velocity of the 80. kg skater ?(neglect
frictional effects) 0.13
m/s west 7.5 m/s
west 10.
m/s east 13 m/s
east