Dr. Bullock
FORM - A
Physical Science Exam 3
NAME:
Physical Science Exam 3
Each question is worth 5 points. You may distribute your five points however you wish.
For example, “Question 1-5” will occupy the first five lines of your scantron, “Question
6-10” will occupy the next five lines of your scantron. Each question is worth 5 points
distribute each point on one line of the scantron.
Question 1-5
Acceleration is always in the direction:
A. of the displacement
B. of the initial velocity
C. of the final velocity
D. of the net force
E. opposite to the frictional force
Question 6-10
The term “mass” refers to the same physical concept as:
A. weight
B. inertia
C. force
D. acceleration
E. volume
Question 11-15
When a certain force is applied to the standard kilogram its acceleration is 5.0 m/s 2.
When the same force is applied to another object its acceleration is one-fifth as much.
The mass of the object is:
A. 0.2kg
B. 0.5kg
C. 1.0kg
D. 5.0kg
E. 10 kg
Dr. Bullock
FORM - A
Physical Science Exam 3
Question 16-20
According to Newton's 2nd Law of motion, acceleration...?
A. is proportional to the net force and inversely proportional to the mass
B. is proportional to the net force and inversely proportional to the velocity
C. is proportional to the mass and inversely proportional to the velocity
D. is proportional to the velocity and inversely proportional to the friction
E. is proportional to the mass and inversely proportional to the net force
Question 21-25
The block shown moves with constant velocity on a horizontal surface. Two of the forces
on it are shown. A frictional force exerted by the surface is the only other horizontal
force on the block. The frictional force is:
A.
B.
C.
D.
E.
0
2N, leftward
2N, rightward
slightly more than 2N, leftward
slightly less than 2N, leftward
Question 26-30
The weight of an object is:
A. the quantity of matter it contains
B. the force with which it is attracted by gravity
C. identical to its inertia
D. the same quantity as its mass, except expressed in different units
E. none of these
Question 31-35
A car travels east at constant velocity. The net force on the car is:
A. east
B. west
C. up
D. down
E. zero
Dr. Bullock
FORM - A
Physical Science Exam 3
Question 36-40
You stand on a spring scale on the floor of an elevator. Of the following, the scale shows
the highest reading when the elevator:
A. moves upward with increasing speed
B. moves upward with decreasing speed
C. remains stationary
D. moves downward with increasing speed
E. moves downward at constant speed
Question 41-45
The speed at which air resistance (drag) matches the Earth’s gravitational pull resulting
in a constant fall rate is known as
A. acceleration of gravity
B. acceleration of drag
C. drag velocity
D. gravitational velocity
E. terminal velocity
Question 46-50
A lead block is suspended from your hand by a string. The reaction to the force of
gravity on the block is the force exerted by:
A. the string on the block
B. the block on the string
C. the string on the hand
D. the hand on the string
E. the block on Earth
Question 51-55
A brick slides on a horizontal surface. Which of the following will increase the magnitude
of the frictional force on it?
A. Putting a second brick on top
B. Decreasing the surface area of contact
C. Increasing the surface area of contact
D. Decreasing the mass of the brick
E. None of the above
Question 56-60
The coefficient of kinetic friction:
A. is in the direction of the frictional force
B. is in the direction of the normal force
C. is the ratio of force to area
D. can have units of newtons
E. is none of the above
Dr. Bullock
FORM - A
Physical Science Exam 3
Question 61-65
A 1000-kg airplane moves in straight flight at constant speed. The force of air friction is
1800 N. The net force on the plane is:
A. zero
B. 11800 N
C. 1800 N
D. 9800 N
E. none of these
Question 66-70
Antilock brakes keep the car wheels from locking and skidding during a sudden stop.
Why does this help slow the car down?
A. µk > µs so sliding friction is better
B. µk > µs so static friction is better
C. µs > µk so sliding friction is better
D. µs > µk so static friction is better
E. none of the above
Question 71-75
A box of weight 100 N is at rest on a floor where ms = 0.5. A rope is attached to the box
and pulled horizontally with tension T = 30 N. Which way does the box move?
A. moves to the left
B. moves to the right
C. moves up
D. moves down
E. the box does not move
Question 76-80
From rest, we step on the gas of our Ferrari, providing a force F for 2 secs. During this
time, the car moves 10 m. If the same force would be applied for 6 secs, how much
would the car have traveled during this time?
A. 20 m
B. 30 m
C. 60 m
D. 100 m
E. 90 m
Dr. Bullock
FORM - A
Physical Science Exam 3
Question 81-85
An object of mass m and another object of mass 2m are each forced to move along a
circle of radius 1.0m at a constant speed of 1.0m/s. The magnitudes of their
accelerations are:
A. equal
B. in the ratio of √2 : 1
C. in the ratio of 2 : 1
D. in the ratio of 4 : 1
E. zero
Question 86-90
An object moves around a circle. If the radius is doubled keeping the speed the same
then the magnitude of the centripetal force must be:
A. twice as great
B. half as great
C. four times as great
D. one-fourth as great
E. the same
Question 91-95
If a satellite moves above Earth’s atmosphere in a circular orbit with constant speed,
then:
A. its acceleration and velocity are always in the same direction
B. the net force on it is zero
C. its velocity is constant
D. it will fall back to Earth when its fuel is used up
E. its acceleration is toward the Earth
Dr. Bullock
FORM - A
Physical Science Exam 3
Question 96-100
A rider in a “barrel of fun” finds herself stuck with her back to the wall. Which diagram
correctly shows the forces acting on her?
Dr. Bullock
FORM - A
Physical Science Exam 3
NAME:
You must show your work to get full credit.
Block A, with a mass of 50 kg, rests on a horizontal table top. The coefficient of static
friction is 0.40. A horizontal string is attached to A and passes over a massless,
frictionless pulley and is attached to block B, with a mass 30 kg as shown.
A
B
1. On the drawing of block A below, draw and label all the forces acting on the
object (4 points):
A
2. What is the weight of block A (2 points)?
Dr. Bullock
FORM - A
Physical Science Exam 3
3. What is the frictional force on block A (2 points)?
4. On the drawing of block B below, draw and label all the forces acting on the
object (4 points):
B
5. What is the weight of block B (2 points)?
6. Is the mass of block B enough to move block A? Why or why not? (2 points)