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Forces and Motion Practice Tests

These Grade 8 Science practice tests cover pushes and pulls, newtons, net force, balanced and unbalanced forces, gravity, friction, mass, weight, speed, acceleration, motion graphs, free-body diagrams, and introductory Newton laws.

Skills covered

  • Identifying force, net force, balanced forces, and unbalanced forces
  • Distinguishing mass from weight and contact from noncontact forces
  • Calculating and interpreting speed, acceleration, and simple F = ma relationships
  • Reading distance-time graphs and force diagrams
  • Applying inertia and Newton laws to everyday motion and safety situations

How to use these practice tests

Draw or imagine the force arrows first. Add opposite forces carefully to find net force, then decide whether the object accelerates. For numerical questions, write the relationship, substitute the known values, and check the units.

For more Grade 8 Science practice, return to the Grade 8 Science category.

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Grade 8 Forces and Motion Practice Tests

Practice Grade 8 Science questions about forces, net force, balanced forces, friction, gravity, mass, weight, speed, acceleration, graphs, and Newton laws.

Choose the best answer for each question. Analyze force diagrams, motion data, graphs, mass, acceleration, friction, gravity, and Newton law relationships.

10 Questions
0/10 Questions0 %
Correct 0
Incorrect 0
Unanswered 10
1. QuestionMultiple choice

What is speed?

Please select an answer first.

Correct answer: A

The correct answer is The distance an object travels per unit of time.

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

Speed can be calculated as distance divided by time, written as v = d / t.

2. QuestionMultiple choice

What is acceleration?

Please select an answer first.

Correct answer: B

The correct answer is A change in velocity over time.

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

Acceleration occurs when speed, direction, or both change over time.

3. QuestionMultiple choice

What does the slope of a distance-time graph represent?

Please select an answer first.

Correct answer: C

The correct answer is Speed.

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

The change in distance divided by the change in time gives speed on a distance-time graph.

4. QuestionMultiple choice

What does a horizontal line on a distance-time graph represent?

Please select an answer first.

Correct answer: D

The correct answer is The object is not changing position..

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

A horizontal distance-time line means distance stays constant as time passes.

5. QuestionMultiple choice

An object travels 60 meters in 12 seconds. What is its average speed?

Please select an answer first.

Correct answer: A

The correct answer is 5 m/s.

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

Average speed equals distance divided by time: 60 m / 12 s = 5 m/s.

6. QuestionMultiple choice

If the same net force acts on two objects, which object has greater acceleration?

Please select an answer first.

Correct answer: B

The correct answer is The object with less mass.

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

From F = ma, a fixed force produces greater acceleration when mass is smaller.

7. QuestionMultiple choice

How does friction usually affect a sliding object?

Please select an answer first.

Correct answer: C

The correct answer is It reduces the objects motion in the direction of sliding..

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

Friction acts opposite the relative motion between the object and the surface.

8. QuestionMultiple choice

Why can a falling object eventually stop increasing its speed?

Please select an answer first.

Correct answer: D

The correct answer is Air resistance can grow until it balances the downward force of gravity..

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

When upward air resistance balances downward gravity, net force approaches zero and speed can become constant.

9. QuestionMultiple choice

A cart moves east and experiences a larger force east than west. What happens?

Please select an answer first.

Correct answer: A

The correct answer is The cart accelerates east..

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

The larger eastward force creates an eastward net force and acceleration.

10. QuestionMultiple choice

Why does a car passenger move forward when the car stops suddenly?

Please select an answer first.

Correct answer: B

The correct answer is Inertia keeps the passenger moving forward until another force acts..

  1. Identify the motion information: Find the direction, distance, time, speed, acceleration, mass, or force described in the situation or data.
  2. Compare forces: Determine whether forces are balanced, calculate the net force when possible, and connect the result to motion.
  3. Apply the model: Use Newton law relationships, diagrams, graphs, or observations to explain the change in motion.

The passengers motion continues due to inertia, so a seat belt provides the force needed to slow the passenger.

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