Download Forces and Motion

8th Grade Science
Name: _________________________________
Period: ___________
Date: ______________
Physical Science: Forces and Motion Test
Match the term with the corresponding definition. Write the letter of the definition on the
provided line.
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_______ Motion
_______ Speed
_______ Velocity
_______ Acceleration
_______ Force
_______ Net Force
A.
B.
C.
D.
E.
F.
A push or pull exerted on ab object.
A change in position with respect to a reference point.
The overall force on an object when all the individual forces acting on it are added together.
Speed in a given direction.
The distance an object travels per unit of time.
The rate at which velocity changes.
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_______ Friction
_______ Gravity
_______ Free Fall
_______ Air Resistance
_______ Inertia
________ Momentum
G.
H.
I.
J.
K.
L.
The fluid friction experienced by objects falling through the air.
The product of an object’s mass and velocity.
The motion of a falling object when the only force acting on it is gravity.
The force that one surface exerts on another when the two surfaces rub against each other.
The tendency of an object to resist any change in its motion.
The force that pulls objects toward each other.
13. ____________ An object that is moving at a constant speed will be accelerating if it is?
A. Moving in a straight line
B. Moving a in a curved line
C. Moving away from you
14. ____________ When you are riding in a car and the car stops suddenly, you continue to move forwards because of?
A. friction
B. gravity
C. inertia
15. ____________ Ivan is doing an experiment with bowling balls. He sets four balls rolling at the same speed/acceleration. Ball 1
has a mass of 9kg, ball 2 has a mass of 8kg, and ball 3 has a mass of 5kg. Which ball will hit the bowling pins with the most
force?
A. Ball 1
B. Ball 2
C. Ball 3
16. ___________ A girl jumps forward off a boat. According to Newton’s Third Law of Motion, what happens to the boat?
A. The boat also moves forward.
B. The boat remains motionless.
C. The boat moves backward.
17. ___________ Gillian attached a block to a spring scale and put the block on her desk. She pulled gently on the spring scale
until the block just barely started moving. The spring scale read 15N. Gillian had to use 15N of forces to overcome the force of?
A. Drag Fluid Friction
B. Static Friction
C. Sliding Friction
18. ___________ According to the Law of Conservation of Momentum, when two objects collide in the absence of friction?
A. Velocity decreases.
B. Velocity Increases.
C. Momentum is not lost.
8th Grade Science
19.
___________ Using the diagram above, what is the acceleration of the ball between 0 and 3 seconds?
A. 1 m/s²
B. 2 m/s²
C. 3 m/s²
20. ____________The standard units for measuring the length of a distance include?
A. meters
B. centimeters
C. feet
21. ____________ In this diagram,?
A. the force of gravity is greater between the objects in pair 1 than between the
objects in Pair 2 because the objects in Pair 1 are closer together.
B. the force of gravity is greater between the objects in Pair 2 than between the
objects in pair 1 because the objects in Pair 2 are closer together.
C. the force of gravity is greater between the objects in Pair 2 than between the
objects in Pair 1 because the objects in Pair 2 have more mass.
22. ____________ Colleen used a ruler to measure the distance a snail traveled along the sidewalk. What was the snail’s average
speed for these three minutes?
A. 1.78 cm/min.
B. .21 cm/min.
C. .59 cm/min.
23. ____________ The standard unit for measuring an amount of force include?
A. kg x m/s
B. Newton
C. m/s²
24. ___________ Which force causes the downward curving motion of the basketball into a hoop as it is shot by a basketball
player?
A. The balanced force exerted by the basketball player
B. The balanced force of gravity
C. The unbalanced force of gravity
25. ___________ A marble is released at the top of an inclined plane (ramp). The forces acting on the marble are?
8th Grade Science
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A. decreasing
B. balanced
C. unbalanced
____________ When traveling forward in a moving car; why do trees outside appear to be moving backwards?
A. You are judging the motion as if you were stationary.
B. The wind is blowing the trees.
C. The moving car affects your balance.
___________ When unbalanced forces act on a nonmoving object, the object must?
A. Remain motionless
B. Begin moving
C. Slow down
__________ Forces have both direction and
A. length
B. speed
C. magnitude
__________ What happens when an unbalanced force acts on an object?
A. The object moves or changes its motion
B. The object does not change its motion
C. Another force stops acting on the object
__________ If two students each push a box with a force of 3 N in the same direction and there is no other unbalanced force
on the box, what is the magnitude of the net force exerted on the box?
A. 0 N
B. 3 N
C. 6 N
__________ An apple falls from a tree. If the weight of the apple is the action force, what is the reaction force?
A. The apple’s pull on the Earth.
B. The Force of air particles against the apple
C. The gravitational pull on the apple
__________ Carla pushes on a box with a force of 28 Newtons (N), and the box accelerates 0.4 meters per second squared
(m/s²). What is the mass in kilograms (kg), of the box?
A. 11.2 kg
B. 56 kg
C. 70 kg
In the diagrams below, g is the force of gravity, r is the force of the ramp acting on the car and f is the force of friction. Which
diagram shows the directions of the forces acting on the car as it travels down the ramp? Circle the correct force diagram.
34. A. Which has more momentum; a 250 kg dolphin swimming at 4 m/s, or a 350 kg manatee swimming at 2 m/s?
B. Which would be harder to place a force to make it slow down or even stop? Why?
35. Look at the diagram below of the two students pulling a bag of volleyball equipment across carpeted floor. The friction force
between the bag and the floor is 15 N.
a. Identify on the diagram the positive and negative vector values.
b. What is the net force acting on the bag? (Show your work)
c.
Identify whether the system is balanced or unbalanced.
d.
If the equipment bag has a mass of 75 kg, what is the acceleration of the bag?
e.
Explain what the positive acceleration value means to the movement of the bag.
f.
Explain how the students could make pulling the bag much easier.
8th Grade Science
36. Short Answer How could you keep an object’s acceleration the same if the force acting on the object were doubled?
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Short Answer/ Essay Use the information in the below diagram to answer the following question(s). Name two forces that
acted on the blocks as they were moving down the ramps. Describe how each force you listed affected the motion of the block.
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