Worksheets8th Grade Forces, Motion, Gravity Mid-Unit Test Review
Total questions: 40
Worksheet time: 20mins
Name
Class
Date
1.
Four forces are acting on a box, as shown below.This box will increase in speed
a)
downward and to the left.
b)
downward and to the right.
c)
upward and to the left.
d)
upward and to the right.
2.
What is one way you could reduce the friction between two surfaces?
a)
put salt on the surfaces
b)
put sand on the surfaces
c)
put carpet on the surfaces
d)
put oil on the surfaces
3.
Kara pushes her big brother on a swing at the playground. After he gets off the swing, her little brother gets on. Kara finds that it is easier to push her little brother than it was to push her big brother.What is the MOST LIKELY reason for this?
a)
A smaller mass always moves faster than a larger mass.
b)
A smaller mass always moves slower than a larger mass.
c)
Less force is needed to move a larger mass the same distance.
d)
More force is needed to move a larger mass the same distance.
4.
Objects tend to keep on doing what they are doing. This natural tendency to resist change in motion is called ___________
a)
inertia
b)
acceleration
c)
friction
d)
momentum
5.
What type of force causes an ice skater to begin to move?
a)
balanced
b)
gravitational
c)
magnetic
d)
unbalanced
6.
The diagram below shows a person pulling on a crate. The arrows show the forces acting on the crate. The numbers indicate the sizes of the forces.What is the net force (sum of the forces) acting on the crate?
a)
15 N to the left
b)
447 N up
c)
475 N to the right
d)
894 N down
7.
Which of these is one of Newton’s laws of motion?
a)
An object’s momentum is the product of its mass and velocity.
b)
A moving object will continue moving until a force acts upon it.
c)
The force of gravity is proportional to the inverse square of the distance.
d)
The rate at which an object falls depends on the height from which it is dropped.
8.
Which equation expresses Newton’s second law of motion?
a)
F = ma
b)
F = m/a
c)
F = m - a
d)
F = m + a
9.
If all of the objects in the data table below have the same acceleration, which object will require the greatest force?
a)
1
b)
2
c)
3
d)
4
10.
Which of the following indicate that an object has been subjected to an unbalanced force?
a)
The object speeds up.
b)
The object slows down.
c)
The object changes direction.
d)
Any of the above.
11.
Tim pulls on a rope with a force of 50 N and Mike pulls on the same rope with a force of 40 N, as shown below.Which statement describes the motion of the rope?
a)
The rope moves toward Tim.
b)
The rope does not move at all.
c)
The rope moves toward Mike.
d)
The rope sags toward the ground.
12.
Which of Newton’s laws best explains why motorists should buckle-up?
a)
1st law
b)
2nd law
c)
3rd law
d)
the law of gravitation
13.
When the air is released from a balloon, the air moves in one direction, and the balloon moves in another direction. Which statement does this situation best illustrate?
a)
What goes up must come down.
b)
For every action there is an equal and opposite reaction.
c)
The shape and size of an object affect air resistance.
d)
The acceleration due to Earth’s gravity is 9.8 m/s2
14.
When you walk across the ground and push on it with your feet. . .
a)
There is no effect on the ground.
b)
The ground pushes back less strongly than your feet.
c)
The ground pushes back more strongly than your feet
d)
The ground pushes back on your feet with equal force.
15.
What kind of friction occurs when objects are not moving?
a)
sliding
b)
rolling
c)
static
d)
fluid
16.
Which best describes how forces must interact for a kite to sail up into the air?
a)
The force of gravity must be equal to the force of the wind.
b)
The force of gravity must be greater than the wind
c)
The force of the wind must be greater than the force of gravity.
d)
The force of the person flying the kite must be equal to the force of the wind.
17.
A 10-newton force and a 15-newton force are acting from a single point in opposite directions.What additional force must be added to produce equilibrium?
a)
5 N acting in the same direction as the 10-N force
b)
5 N acting in the same direction as the 15-N force
c)
10 N acting in the same direction as the 10-N force
d)
25 N acting in the same direction as the 15-N force
18.
An object moving along a surface suddenly increases speed. What can cause this to happen?
a)
It is moved by balanced forces.
b)
It is moved by two opposite forces.
c)
It is moved by an unbalanced force.
d)
It is moved by a force without direction.
19.
An astronaut applies a force to a keyboard that is attached to the wall of a space shuttle.After the astronaut applies the force to the keyboard, the astronaut moves
a)
faster and upward
b)
at a uniform speed and downward
c)
at a uniform speed and away from the keyboard
d)
faster and toward the keyboard at a constant rate.
20.
A student sets a block at the top of a wooden ramp.The student pushes the block. As the block slides down the ramp, it slows down and then comes to a stop. What force causes the block to slow down?
a)
the force of gravity
b)
the force of friction
c)
the force of magnetism
d)
the force of the student’s push
21.
A 2000 kg car is pulling a 1000 kg trailer. The car’s engine exerts a 6000 N force to move the car and the trailer. In addition, the car and the trailer each experience a 1000 N frictional force as they are being pulled, as represented below.What is the magnitude of the net force on this system?
a)
2000 N
b)
4000 N
c)
5000 N
d)
8000 N
22.
What kind of friction occurs when Jackson dives head first into home plate at the baseball game?
a)
sliding
b)
rolling
c)
static
d)
fluid
23.
Which statement best describes what must happen in order for a person to lift an object?
a)
The force of gravity must be greater than the mass of the object.
b)
The mass of the object must be greater than the force of gravity.
c)
The force of gravity must be greater than the upward pull or push on the object.
d)
The upward pull or push on the object must be greater than the force of gravity.
24.
A child jumps on a trampoline, as shown above.Which of the following causes the child to rise in the air?
a)
Inertia
b)
Mass
c)
A reaction force
d)
A gravitational force
25.
In the picture above, a boy is trying to pull a dog on a leash, but the dog and the boy are moving in the same direction. Which of the following best describes the forces in this situation?
a)
The forces are balanced, and the net force is zero.
b)
The forces are unbalanced, and the boy’s force is greater.
c)
The forces are unbalanced, and the dog’s force is greater.
d)
The forces are balanced, and the dog is stronger than the boy.
26.
A teacher leaves a coffee mug on top of a car, as shown in the diagram below.The teacher drives the car in a straight line and then stops suddenly. What happens to the coffee mug when the car stops?
a)
The mug moves forward.
b)
The mug moves backward.
c)
The mug moves side to side.
d)
The mug stays in the same position.
27.
Mrs. Spendiff's 4th period is conducting a motion experiment to see which surface would allow a golf ball to go the maximum distance before stopping. Which surface listed below would work the best?
a)
a sandy surface
b)
a grassy surface
c)
an icy surface
d)
a carpeted surface
28.
The following picture shows Tasha pulling a wagon holding her brother.Tasha notices that even though she stops pulling the wagon, her brother’s body moves forward.Which of Newton’s laws of motion explains Tasha’s observation?
a)
The first law, in which an object moves forward in a straight line unless acted upon by an outside force
b)
The second law, in which force is a product of an object’s acceleration and mass
c)
The third law, in which every action has an equal and opposite reaction
d)
The fourth law, in which energy is never lost but is transformed from one object to another
29.
What happens to the motion of a moving object when the net force (sum of the forces) acting on it is zero?
a)
The object travels in a straight line at a constant
b)
The object comes to rest due to opposing forces.
c)
The object speeds up in the direction of the greater force.
d)
The object changes direction while moving at a constant speed.
30.
A ball rolling on the ground is observed to slow down and stop. Based on Newton’s first law of motion, what is the best conclusion?
a)
An object in motion eventually stops.
b)
The ball must have been going slightly uphill.
c)
The ball did not have enough mass to keep going.
d)
There must have been an outside force acting on the ball.
31.
What is Mass?
a)
The amount of space an object takes up
b)
The amount of matter in an object
c)
The pull of gravity on an object
d)
Mass divided by volume
32.
A push or pull on an object is called a
a)
force
b)
mass
c)
acceleration
d)
work
33.
A ball is thrown straight up into the air. What force is acting on the ball while it is in the air?
a)
Both gravity and air resistance
b)
No forces
c)
Only gravity
d)
Only air resistance
34.
Which of the following scenarios best illustrates Newton's third law of motion?
a)
A book resting on a table
b)
A person pushing against a wall and the wall pushing back
c)
A ball rolling down a hill
d)
A car accelerating on a highway
35.
What happens to the acceleration of an object if the net force acting on it is doubled?
a)
The acceleration is halved
b)
The acceleration remains the same
c)
The acceleration is doubled
d)
The acceleration is quadrupled
36.
Which of the following scenarios best illustrates Newton's third law of motion?
a)
A car accelerating on a highway
b)
A rocket launching into space
c)
A ball rolling down a hill
d)
A book resting on a table
37.
What is the effect of increasing the mass of an object on its acceleration, assuming the force applied remains constant?
a)
The acceleration becomes zero
b)
The acceleration decreases
c)
The acceleration increases
d)
The acceleration remains the same
38.
When a person is standing still on the ground, which forces are acting on them?
a)
Only gravitational force
b)
Only normal force
c)
No forces
d)
Both gravitational and normal forces
39.
Which of the following best describes the relationship between mass and weight?
a)
Mass is the same as weight.
b)
Weight is mass multiplied by the acceleration due to gravity.
c)
Mass is weight divided by the acceleration due to gravity.
d)
Weight is the amount of matter in an object.
40.
If a car is moving at a constant speed on a straight road, what can be said about the net force acting on it?
a)
The net force is equal to the car's mass.
b)
The net force is equal to the car's weight.
c)
The net force is equal to the car's acceleration.
d)
The net force is zero.
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