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Physics 101
Test 2
5 October 2016
Multiple Choice. Choose the best answer to each question. No partial credit given.
Each question is worth 3.030303 points.
____1.
If my sister pushes on a sled with 20 Newtons of force for 5 meters, how much work was
done on the sled?
a) 0.25 Joules b) 4 Joules c) 100 Joules d) 500 Joules
____2.
How much energy is expended when a 300 Watt light bulb is turned on for 5 seconds?
a) 6 Joules
b) 60 Joules c) 150 Joules d) 1500 Joules
Use the drawing to the right to answer questions 3-7.
The 40 kg person at the top of the dive is initially at rest.
____3.
What is the potential energy of the person at the bottom of the dive?
a) 4000 J
b) 2000 J
c) 400J
d) 0 J
____4.
What is the potential energy of the person when she is halfway down?
a) 4000 J
b) 2000 J
c) 400 J
d) 0 J
____5.
What is the velocity of the diver just before hitting the water?
a) 0.141 m/s b) 1.41 m/s c) 14.1 m/s
d) 141 m/s
____6.
Which is greater, the potential energy at 5m or the kinetic energy at 5 m?
a) PE at 5 m
b) KE at 5 m
c) Both are same
____7.
What is the kinetic energy halfway down?
a) 4000 J
b) 2000 J
c) 400J
10 m
d) 0 J
____8.
A 1000 kg car is lifted 3 meters while a 1500 kg car is lifted 2 m. Raising the lighter car
requires
a) half the work b) twice as much work c) four times the work d) the same work
____9.
An object that has gravitational potential energy must be
a) moving
b) falling
c) at an elevated position
d) at rest
____10.
A water balloon with a weight of 10 N is dropped from a height of 30 m. Its kinetic energy
just before hitting the ground is
a) 10 J
b) 3 J
c) 300 J
d) 310 J
____11.
Which has a greater kinetic energy, a 5 kg mass traveling at 20 m/s or a 2.5 kg mass
traveling at 40m/s?
a) the 5 kg
b) the 2.5 kg mass
c) both have same KE
____12.
A bird at a height of 20 m has 100 J of potential energy. What is its mass
a) 5 kg
b) 50 kg
c) 0.5 kg
d) 0.05 kg
____13.
Which requires the most amount of work on the brakes of a 500 kg car?
a) slowing down from 3 m/s to 0 m/s
b) slowing down from 6 m/s to 3 m/s
c) Equal amounts of work for both
____14.
A machine that is 10% efficient accomplishes 50 joules of work. How much energy had to
be input into the machine?
a) 50 J
b) 500 J
c) 20 J
d) 200 J
____15.
A car moving at 20 m/s skids 8 m with locked brakes. How far will the car skid
with locked brakes if it is traveling at 10 m/s?
a) 8 m b) 6 m
c) 4m d) 2 m
____16.
Two objects rotate on a merry-go-round, one at r=1 m and the other at r=2m from the
center. Both objects have the same
a) momentum b) angular velocity c) linear velocity d) rotational inertia
____17.
An upright broom is easier to balance when the heavier end is
a) nearest your hand
b) farthest from your hand
____18.
A torque acting on an object tends to produce
a) equilibrium
b) balance
c) rotation
c) same either way
d) inertia
____19.
If the Earth expanded to twice its diameter with the same mass, its rate of rotation
about its axis would
a) decrease b) increase c) stay same d) more info needed
____20.
A car travels in a circle with constant speed. The net force on the car
a) directed forward, in the direction of travel
b) directed towards the center of the curve
c) zero because the car is not accelerating
d) none of these
____21.
If the earth rotated faster about its axis, your apparent weight would
a) increase
b) decrease
c) stay same
____22.
A 50 kg boy sits at a distance of 2 m from the center of a see-saw. Where must his 40 kg
sister sit to balance the see-saw?
a) 3 m
b) 2.5 m
c) 2 m
d) 1.5 m
____23.
The centripetal force acting on an object in constant angular motion works to change its
a) angular velocity b) linear speed c) direction of motion d) rotational inertia
____24.
If all of the inhabitants of the earth would climb to the top of a ladder, the angular
speed of the earth would
a) increase b) decrease c) stay same
____25.
To make your bathroom scale read more in the northern hemisphere, you should move
to a location
a) north
b) south
c) east
d) west
____26.
A meter stick (100cm) is balanced at the 10 cm mark when a mass of 0.8 kg is hung at the
0 cm mark. The mass of the stick is
a) 0.9 kg
b) 0.5 kg
c) 0.4 kg
d) 0.2 kg
____27.
If all of the inhabitants of the earth lay down on the ground at the same time, the angular
velocity of the earth’s rotation would
a) increase b) decrease c) stay same
____28.
According to Newton the greater the distance between interacting objects, the
a) less the gravitational force between them
b) less the gravitational force between them by the square of the distance
c) greater the gravitational force between them.
d) greater the force between them by the square of the masses
____29.
If the radius of the earth somehow decreased with no change in mass, your weight would
a) increase b) decrease c) not change
____30.
A satellite in orbit at a distance of one earth radius from the earth’s surface has an
apparent weight in that orbit of 1000 N. When it lands on the earth, the force of gravity
on the satellite is
a) 0 N
b) 1000 N
c) 2000 N
d) 4000 N
____31.
Inside an elevator that is accelerating upwards, your apparent weight is
a) same as at rest
b) zero
c) greater than normal
d) less than normal
____32.
For a satellite orbiting the earth, which must remain constant for the satellite to remain in
orbit?
a) linear speed
b) orbital radius
c) centripetal force d) all of these
____33.
What provides the centripetal force for your car to travel on an off-ramp on the
interstate?
a) momentum
b) normal force
c) gravity
d) friction
Answers on next page!
1c
2d
3d
4b
5c
6c
7b
8d
9c
10 c
11 b
12 c
13 b
14 b
15 d
16 b
17 b
18 c
19 a
20 b
21 b
22 b
23 c
24 b
25 a
16 d
27 a
28 b
29 a
30 d
31 c
32 d
33 d