A 1000 kg sportscar accelerates from zero to 25 m/s in 7.5 s. What is the average power delivered by the automobile engine?

1
A 1000 kg sportscar accelerates from zero to 25
m/s in 7.5 s. What is the average power delivered
by the automobile engine?

1. 20.8 kW
2. 30.3 kW
3. 41.7 kW
4. 52.4 kW

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2
A bobsled makes a run down an ice track starting
at 150 m vertical distance up the hill. If there
is no friction, what is the velocity at the
bottom of the hill?

1. 27 m/s
2. 36 m/s
3. 45 m/s
4. 54 m/s

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3
A jet engine develops 105 N of thrust in moving
an airplane forward at a speed of 900 km/hr. What
is the power developed by the engine?

1. 500 kW
2. 1 MW
3. 2.5 MW
4. 5 MW

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4
A speedboat requires 80 kW to move at a constant
speed of 15 m/s. What is the resistive force of
the water at this speed?

1. 2667 N
2. 5333 N
3. 6500 N
4. 7711 N

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5
A pole vaulter clears 6 m. With what velocity
does he strike the mat in the landing area?

1. 2.7 m/s
2. 5.4 m/s
3. 10.8 m/s
4. 21.6 m/s

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6
A parachutist of mass 50 kg jumps out of an
airplane at a height of 1000 m. The parachute
deploys, and she lands on the ground with a
velocity of 5 m/s. How much energy was lost to
air friction during this jump?

1. 49,375 J
2. 98,750 J
3. 197,500 J
4. 489,375 J

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7
Water flows over a section of Niagara Falls at a
rate of 1.2 x 106 kg/s and falls 50 m. What is
the power wasted by the waterfall?

1. 588 MW
2. 294 MW
3. 147 MW
4. 60 MW

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8
A baseball outfielder throws a baseball of mass
0.15 kg at a speed of 40 m/s and initial angle of
30 . What is the kinetic energy of the baseball
at the highest point of the trajectory? Ignore
air friction.

1. zero
2. 30 J
3. 90 J
4. 120 J

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9
A Russian weightlifter is able to lift 250 kg 2 m
in 2 s. What is his power output?

1. 500 W
2. 2.45 kW
3. 4.9 kW
4. 9.8 kW

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10
A worker pushes a 500 N weight wheelbarrow up a
ramp 50.0 m in length and inclined at 20 with
the horizontal. What potential energy change does
the wheelbarrow experience?

1. 1500 J
2. 3550 J
3. 4275 J
4. 8550 J

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11
A worker pushes a 500 N weight wheelbarrow to the
top of a 50.0 m ramp, inclined at 20 with the
horizontal, and leaves it unattended. The
wheelbarrow is accidentally bumped causing it to
slide back down the ramp during which a 80 N
frictional force acts on it over the 50.0 m. What
is the wheelbarrow's kinetic energy at the bottom
of the ramp? (g 9.8 m/s2 )

1. 4550 J
2. 6550 J
3. 8150 J
4. 13100 J

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12
What is the kinetic energy of a 0.135 kg baseball
thrown at 40 m/s (90 mph)?

1. 54 J
2. 87 J
3. 108 J
4. 216 J

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13
A 15.0 kg crate, initially at rest, slides down a
ramp 2.0 m long and inclined at an angle of 20
with the horizontal. If there is no friction
between ramp surface and crate, what is the
kinetic energy of the crate at the bottom of the
ramp? (g 9.8 m/s2 )

1. 221 J
2. 688 J
3. 10.2 J
4. 100 J

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14
A worker pushes a wheelbarrow with a force of 50
N over a level distance of 5 m. If a frictional
force of 43 N acts on the wheelbarrow in a
direction opposite to that of the worker, what
net work is done on the wheelbarrow?

1. 250 J
2. 215 J
3. 35 J
4. 10 J

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15
If during a given physical process the only force
acting on an object is friction, which of the
following must be assumed in regard to the
object's kinetic energy?

1. decreases
2. increases
3. remains constant
4. cannot tell from the information given

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16
As an object is lowered into a deep hole in the
surface of the earth, which of the following must
be assumed in regard to its potential energy?

1. increase
2. decrease
3. remain constant
4. cannot tell from the information given

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17
When an object is dropped from a tower, what is
the effect of the air resistance as it falls?

1. does positive work
2. increases the object's kinetic energy
3. increases the object's potential energy
4. None of these choices are valid.

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18
The unit of work, joule, is dimensionally the
same as which of the following?

1. newton/second
2. newton/kilogram
3. newton-second
4. newton-meter

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19
The unit of power, watt, is dimensionally the
same as which of the following?

1. joule-second
2. joule/second
3. joule-meter
4. joule/meter

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20
The rate at which work is done is equivalent to
which of the following?

1. increase in potential energy
2. thermal energy
3. potential energy
4. power

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21
A worker pushes a wheelbarrow with a horizontal
force of 50 N over a distance of 5 m. What work
does the man do?

1. 10 J
2. 1250 J
3. 250 J
4. 55 J

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22
A 40 N crate is pulled up a 5 m inclined plane at
a constant velocity. If the plane is inclined at
an angle of 37 to the horizontal and there
exists a constant force of friction of 10 N
between the crate and the surface, what is the
net gain in potential energy by the crate in the
process?

1. 120 J
2. -120 J
3. 200 J
4. -200 J

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23
A 40 N crate starting at rest slides down a rough
6 m long ramp, inclined at 30 with the
horizontal. The force of friction between crate
and ramp is 6 N. What will be the velocity of the
crate at the bottom of the incline?

1. 1.6 m/s
2. 3.3 m/s
3. 4.5 m/s
4. 6.4 m/s

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24
Which of the following is an example of a
non-conservative force?

1. gravity
2. magnetism
3. Both magnetism and gravity
4. friction

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25
Which of the following is that form of energy
associated with an object's motion?

1. potential
2. thermal
3. bio-chemical
4. kinetic

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26
Which of the following is that form of energy
associated with an object's location in a
conservative force field?

1. potential
2. thermal
3. bio-chemical
4. kinetic

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27
A 50 N crate is pulled up a 5 m inclined plane by
a worker at constant velocity. If the plane is
inclined at an angle of 37 to the horizontal and
there exists a constant force of 10 N between the
crate and the surface, what is the force applied
by the worker?

1. zero
2. 20 N
3. 30 N
4. 40 N

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28
A small wagon moving at constant velocity carries
a 200 N crate 10 m across a level surface. What
is the net work done in the process?

1. zero
2. 1/20 J
3. 20 J
4. 2000 J

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29
The quantity of work equal to one joule is also
equivalent to which of the following?

1. watt
2. watt/s
3. watt x s
4. watt/s2

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30
A 3 kg object starting at rest falls to the
ground from a height of 10 m. Just before hitting
the earth what will be its kinetic energy? (g
9.8 m/s2 and assume air resistance is
negligible.)

1. 98 J
2. 0.98 J
3. 29.4 J
4. 294 J

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31
An arrow, shot straight up from a crossbow has an
initial velocity of 50 m/s. Ignore energy lost to
air friction. How high will the arrow rise?

1. 49 m
2. 62.4 m
3. 98 m
4. 127.5 m

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32
What is the minimum amount of energy required for
an 80-kg climber carrying a 20-kg pack to climb
Mt. Everest, 8850 m high?

1. 8.67 mJ
2. 4.16 mJ
3. 2.47 mJ
4. 1.00 mJ

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33
A professional skier reaches a speed of 56 m/s on
a 30 ski slope. Ignoring friction, what is the
minimum distance along the slope the skier would
have to travel, starting from rest?

1. 110 m
2. 160 m
3. 320 m
4. 640 m

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34
A girl and her bicycle have a total mass of 40
kg. At the top of the hill her speed is 5 m/s.
The hill is 10 m high and 100 m long. If the
force of friction as she rides down the hill is
20 N, what is her speed at the bottom?

1. 5 m/s
2. 10 m/s
3. 11 m/s
4. She stops before she reaches the bottom.

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35
Old Faithful geyser in Yellowstone Park shoots
water more or less hourly to a height of 40
meters. With what velocity does the water leave
the ground?

1. 7.0 m/s
2. 14.0 m/s
3. 19.8 m/s
4. 28.0 m/s

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36
An 80,000 kg airliner is flying at 900
kilometers/hour at a height of 10 kilometers.
What is its total energy (kinetic potential)?

1. 250 MJ
2. 478 MJ
3. 773 MJ
4. 10,340 MJ

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37
A 1200 kg automobile moving at 25 m/s has the
brakes applied with a deceleration of 8 m/s2 .
How far does the car travel before it stops?

1. 39 m
2. 47 m
3. 55 m
4. 63 m

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38
A girl and her bicycle have a total mass of 40
kg. At the top of the hill her speed is 5 m/s and
her speed doubles as she rides down the hill. The
hill is 10 m high and 100 m long. How much
kinetic energy and potential energy is lost to
friction?

1. 2420 J
2. 1500 J
3. 2000 J
4. 3920 J

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39
A 60 g golf ball is dropped from a height of 2 m
and rebounds to 1.5 m. How much energy is lost?

1. 0.29 J
2. 0.5 J
3. 0.88 J
4. 1 J

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40
A golf ball hits a wall and bounces back at 3/4
the original speed. What part of the original
kinetic energy of the ball did it lose in the
collision?

1. 1/4
2. 3/8
3. 7/16
4. It did not lose kinetic energy.

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41
If both the mass and the velocity of a ball are
tripled, the kinetic energy is increased by a
factor of

1. 3
2. 6
3. 9
4. 27

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42
A 2 kg ball which originally has zero kinetic and
potential energy is dropped into a well which is
10 m deep. Just before the ball hits the bottom,
the sum of its kinetic and potential energy is

1. 0
2. 196 J
3. -196 J
4. 392 J

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43
A 2 kg ball which originally has zero potential
and kinetic energy is dropped into a well which
is 10 m deep. After the ball comes to a stop in
the mud, the sum of its potential and kinetic
energy is

1. 0
2. 196 J
3. -196 J
4. 392 J

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44
A hill is 100 m long and makes an angle of 12
with the horizontal. As a 50 kg jogger runs up
the hill, how much work does gravity do on the
jogger?

1. 49,000 J
2. 10,000 J
3. -10,000 J
4. zero

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45
Two blocks are released from the top of a
building. One falls straight down while the other
slides down a smooth ramp. If all friction is
ignored, which one is moving faster when it
reaches the bottom?

1. The block that went straight down.
2. The block that went down the ramp.
3. They both will have the same speed.
4. Insufficient information to work the problem.

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46
A simple pendulum, 2.0 m in length, is released
by a push when the support string is at an angle
of 25 from the vertical. If the initial speed
of the suspended mass is 1.2 m/s when at the
release point, to what maximum angle will it move
in the second half of its swing? (g 9.8 m/s2 )

1. 37
2. 30
3. 27
4. 21

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47
An automobile delivers 30 hp to its wheels when
moving at a constant speed of 22 m/s. What is the
resistance force on the automobile at this speed?
(1 hp 746 watts)

1. 18,600 N
2. 410,000 N
3. 1,020 N
4. 848 N

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48
I use a rope to swing a 10 kg weight around my
head. The rope is 2 m long and the tension in the
rope is 20 N. In half a revolution how much work
is done by the rope on the weight?

1. 40 J
2. 126 J
3. 251 J
4. 0

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49
The work done by static friction is always

1. positive
2. negative
3. along the surface
4. zero

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50
A simple pendulum, 2.0 m in length, is released
with a push when the support string is at an
angle of 25 from the vertical. If the initial
speed of the suspended mass is 1.2 m/s when at
the release point, what is its speed at the
bottom of the swing? (g 9.8 m/s2 )

1. 2.3 m/s
2. 2.6 m/s
3. 2.0 m/s
4. 0.5 m/s

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51
A horizontal force of 200 N is applied to a 55 kg
cart across a 10 m level surface. If the cart
accelerates at 2.0 m/s2 then what force of
friction acts to retard the motion of the cart?

1. 110 N
2. 90 N
3. 80 N
4. 70 N

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52
A baseball catcher puts on an exhibition by
catching a 0.15 kg ball dropped from a helicopter
at a height of 101 m. What is the speed of the
ball just before it hits the catcher's glove 1.0
m above the ground? (g 9.8 m/s2 and ignore air
resistance)

1. 44.3 m/s
2. 38.0 m/s
3. 31.3 m/s
4. 22.2 m/s

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53
A baseball catcher puts on an exhibition by
catching a 0.15 kg ball dropped from a helicopter
at a height of 100 m above the catcher. If the
catcher "gives" with the ball for a distance of
0.75 m while catching it, what average force is
exerted on the mitt by the ball? (g 9.8 m/s2 )

1. 78 N
2. 119 N
3. 196 N
4. 392 N

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54
A horizontal force of 200 N is applied to move a
55 kg cart across a 10 m level surface. What work
is done by the 200 N force?

1. 4000 J
2. 5400 J
3. 2000 J
4. 2700 J

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55
A simple pendulum, 1.0 m in length, is released
from rest when the support string is at an angle
of 35 from the vertical. What is the speed of
the suspended mass at the bottom of the swing?
(ignore air resistance, g 9.8 m/s2 )

1. 0.67 m/s
2. 0.94 m/s
3. 1.33 m/s
4. 1.88 m/s

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56
A pile driver drives a post into the ground. The
mass of the pile driver is 2500 kg and it is
dropped through a height of 8 m on each stroke.
If the resisting force of the ground is 4 x 106
N, how far is the post driven in on each stroke?

1. 4.9 cm
2. 9.8 cm
3. 16.0 cm
4. 49.0 cm

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57
A 2000-kg ore car rolls 50 meters down a
frictionless 10 incline. If there is a
horizontal spring at the end of the incline, what
spring constant is required to stop the ore car
in a distance of 1 meter?

1. 340.3 kN/m
2. 680.7 kN/m
3. 980.0 kN/m
4. 1960.0 kN/m

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58
An amount of work equal to 1 J is required to
compress the spring in a spring-gun. To what
height can this "gun" shoot a 20-gram marble?

1. 5.1 m
2. 10.2 m
3. 15.3 m
4. 20.4 m

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59
A 60-kg woman runs up a flight of stairs having a
rise of 4 meters in a time of 4.2 seconds. What
average power did she supply?

1. 380 W
2. 560 W
3. 616 W
4. 672 W

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60
A 15.0 kg crate, initially at rest, slides down a
ramp 2.0 m long and inclined at an angle of 20
with the horizontal. If there is no friction
between the ramp surface and crate, what is the
velocity of the crate at the bottom of the ramp?
(g 9.8 m/s2 )

1. 6.1 m/s
2. 3.7 m/s
3. 10.7 m/s
4. 8.3 m/s

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