Unit 3 Test Redo
Old Question
1. If three balls of different materials were dropped at the same time from the same height, which would
hit the ground first? (Assume there is no air resistance)
a. they would all hit at the same time
b. a solid rubber ball
c. a solid steel ball
d. a tennis ball
Answer: A
Explanation
All object’s acceleration due to gravity on Earth is the same. (9.8m/s²) Weight is NOT going to affect the speed
of the object’s fall. Some objects fall slower, like a feather, because of air resistance.
***New Question
1. If three objects of different weights were dropped at the same time from the same height, which would hit
the ground first? (Assume there is no air resistance)
a. a hammer
b. a pen
c. a water bottle
d. they would all hit at the same time
Old Question
2. Walking is an example of
a. Fluid friction
b. Rolling friction
c. Sliding friction
d. Static friction
Answer: C
Explanation
Walking is a type of sliding friction because it is two solid surfaces rubbing against each other. Fluid friction
occurs in liquids or gases. Rolling friction occurs with wheels or round objects. Finally, Static friction occurs
when a force is being applied to an object, but it is not enough to make the object move.
***New Question
2. Swimming is an example of
a. Fluid friction
b. Rolling friction
c. Sliding friction
d. Static friction
Old Question
3. View the free body diagram below
Force A
Force B
What is the direction of the motion of the box?
a. To the right
b. To the left
c. Up
d. Down
Answer: A
Explanation
The force pushing to the right is stronger than the force pushing to the left. It is like tug of war. The bigger
force will overcome the smaller force.
***New Question
3. View the free body diagram below
Force A
Force B
What is the direction of the motion of the box?
a. To the right
b. To the left
c. Up
d. Down
Old Question
4. Parachutes slow sky divers to a safer terminal velocity because parachutes
a. Increase gravitational pull
b. Decrease air resistance
c. Increase air resistance
d. Decrease gravitational pull
Answer: C
Explanation
Parachutes have a large surface area to create MORE air resistance. Air resistance is a type of fluid friction.
We know that friction slows down all moving objects. The more air there is pushing up, the more fluid friction
there will be.
***New Question
4. You compare two pieces of paper that are the same, but are dropped differently. One is dropped flat
so that more surface area is facing the ground. The other is straight up and down so that most of the
surface area is facing away from the ground. The flat paper falls last. Why is this?
a. Increase gravitational pull
b. Decrease air resistance
c. Increase air resistance
d. Decrease gravitational pull
Old Question
5. In every energy conversion, some energy is always converted into
a. Mechanical energy
b. Potential energy
c. Thermal energy
d. Static energy
Answer: C
Explanation
The word thermal means heat. Think about putting hot chocolate in a thermos. The thermos keeps your
thermal (heat) energy inside so that your hot chocolate stays hot.
***New Question
5. When you rub your hands together, some energy is converted into…
a. Mechanical energy
b. Potential energy
c. Thermal energy
d. Static energy
Old Question
6. A car demonstrates two types of friction. The wheels against the road surface and pistons within the
car engine that move up and down in the engine oil. These demonstrate which two types of friction?
e. Fluid and Static
f. Static and Rolling
g. Rolling and Sliding
h. Fluid and Rolling
Answer: D
Explanation
Cars demonstrate both rolling and fluid friction. When the wheels move across the pavement they create
rolling friction. The pistons in the engine create fluid friction because they are interacting with the engine oil.
Oil is a fluid.
***New Question
6. What type(s) of friction are you experiencing in the following scenario: You are running in your house, then
you reach the hardwood floor and plant your feet and glide across the floor to the other side of the room.
When you run and glide what type(s)of friction are you creating?
a. Static and Fluid
b. Rolling and Sliding
c. Just rolling
d. Just sliding
Old Question
7. The force that prevents a ball from rolling on the ground forever is
a. Weight
b. Friction
c. Mass
d. Inertia
Answer: B
Explanation: Friction is the opposing (goes against) force that stops all objects from moving forever. Weight is
gravitational pull on an object. Mass is how much material an object is made of. Inertia is an object’s ability to
resist a change in their motion.
***New Question
7. Why do object slow down because of friction?
a. Because of the moon’s gravitational pull
b. Because of thermal energy
c. Because it acts against the object
d. Because of how much “stuff” the object has
Old Question
8. At what point does a roller coaster have the greatest potential energy?
a. The top of the biggest hill
b. The bottom of the biggest hill
c. The top of the smallest hill
d. The bottom of the smallest hill
Answer: A
Explanation:
Potential Energy is energy due to an objects position. Think of potential energy has energy you build up. The
higher a roller coaster goes the more potential energy it will have. The more you pull back a toy car, the
farther it will travel once released.
***New Question
8.You pull Toy Car A back 12 cm and release it. The car travels 2 m. You take toy car B and pull it back 24 cm
and it travels 4 m. Which car had the greatest potential energy?
a. Toy Car A
b. Toy Car B
c. Both toy cars had the same amount of potential energy.
d. Neither car had any potential energy
Old Question
9. At what point does a roller coaster have the greatest kinetic energy?
a. The top of the biggest hill
b. The bottom of the biggest hill
c. The top of the smallest hill
d. The bottom of the smallest hill
Answer: B
Explanation:
Kinetic Energy is energy in motion. The more potential energy that has been “stored” up the greater the
kinetic energy will be. The coaster cars have been traveling up the first hill which is the tallest in order to
create more energy. At the bottom of that first hill, the car has the greatest kinetic because of amount of
stored energy from moving up the hill.
***New Question
9.You pull Toy Car A back 12 cm and release it. The car travels 2 m. You take toy car B and pull it back 24 cm
and it travels 4 m. Which car had the greatest kinetic energy?
a. Toy Car A
b. Toy Car B
c. Both toy cars had the same amount of potential energy.
d. Neither car had any potential energy
Old Question
10. Friction causes objects to
a. Speed up slowly
b. Speed up quickly
c. Slow down
d. Remain at rest
Answer: C
Explanation:
Friction is a force that goes against an object causing it to slow down. That is why when you stop pedaling your
bike eventually comes to a stop.
***New Question:
10.Weight is to gravitational pull as __________________________is to friction.
a. Slow down
b. Speed up quickly
c. Remain at Rest
d. Speed up slowly
Old Question
11.I walking with sneakers on a gym floor. Afterwards, I travel the same distance with the same stride
length but this time with roller blades on. Would the amount of friction be less with the roller blades?
a. Yes, because they have less surface area and you need less force to move.
b. Yes, because they have more surface area and you need more force to move.
c. No, because they have less surface area and you need less force to move.
d. No, because they have more surface area and you need more force to move.
Answer: A
Explanation:
There is a smaller amount of surface area in contact with the ground so you would need less force to make the
object move. If you were to push someone on roller blades and then push someone else wearing shoes with
the same force, the person on roller blades would move a greater distance supporting the correct answer.
***New Question:
11. Brutus was pulling a sled up the hill. After doing this multiple times he decided to put the sled on a cart
with wheels and take it up the hill. Describe the difference in the amount of friction between the cart with
wheels and pulling the sled up without a cart?
A. There would be the same amount of friction.
B. There would be less friction because there is less surface area in contact with the ground.
C. There would be more friction because there will be more surface area in contact with the ground.
D. There would be more friction because there is more surface area in contact with the ground.
Old Question
Look at the graph below to answer the following questions.
12. Looking at the graph I can conclude that the object is.
e. Moving away from where you began (zero) at a constant speed, then at rest, then returning
back to where you began (zero).
f. Moving towards where you began (zero) at a constant speed
g. Moving away from where you began (zero) central point at a constant speed
h. Moving towards where you began (zero) while decreasing its speed
Answer: C
Explanation:
The x-axis represents the amount of time that has passed as the person is moving away from the central point
also known as zero. This particular person is traveling at a constant speed of 10 meters per second. For every
second they go a distance of 10 meters.
***New Question:
12. Looking at the graph I can conclude that the object is.
a. Moving away from where you began (zero) at a constant rate
b. Moving toward where you began at a constant rate
c. Moving away from where you began (zero) stopping and then continuing to move away from home.
d. Moving towards where you began (zero) while decreasing speed.
Old Question
13. Predict the distance of the object at 7 seconds
a. 60 m
b. 70 m
c. 80 m
d. 90 m
Answer: B
Explanation:
If the person continues to travel at 10 meters per second, after 7 seconds they would have traveled 70 meters.
***New Question:
13. Belle is traveling at a constant rate of 20 feet per minute. How far will Belle travel after 5 minutes
maintaining the constant rate?
a. 20 feet
b. 80 feet
c. 90 feet
d. 100 feet
Old Question
14. In the drawing below, the arrows labeled Force 1 and Force 2 represent two forces acting on an
object. The directions of the arrows show the directions of the forces, and the lengths of the arrows
represent the strength of the forces. What answer choice show an object being acted upon by forces that
do not add up to zero (unbalanced forces).
Answer: D
Explanation:
One easy way to determine if the forces are unbalanced is to determine if the object moves based on the
forces acting on it. If the object moves the forces are unbalance. If the object does not move the forces acting
on the object are balanced. Answer D is the only object in which the object moves. All the other options have
balanced forces acting on them and stay in one spot.
***New Question:
14. Which scenario is an example of a balanced force?
a. Jack pushing right with a force of 40 N and Sumba pulling right with a force of 40 N.
b. Jack pushing right with a force of 40 N and Sumba pushing left with a force of 80 N.
c. Jack pushing right with a force of 40 N and Sumba pushing left with a force of 40 N.
d. Jack pushing right with a force of 40 N and Sumba pulling right with a force of 80 N.
Old Question
15. What will happen to the motion of the box based on the picture below.
10 N
a.
b.
c.
d.

20 N

The box will stay in the same place
The box will move to the right
The box will move to the left
The box will float.
Answer: B
Explanation: In this situation the object has two forces acting on it in the same direction. Because the two
forces are going in the same direction, to find the net force you add them. The net force on this object is 30 N
to the right.
***New Question:
30 N
15.

60 N
What will the net force be acting on this box?
a. 30 N right
b. 90 N right
c. 30 N left
d. 90 N left
