NumicornNumicornLearn, solve, progress

Newton's Laws Introduction Practice Tests

These Grade 8 Science practice tests cover Newton's First, Second, and Third Laws, inertia, balanced and unbalanced forces, net force, F = ma, acceleration, action-reaction pairs, force diagrams, and safety applications.

Skills covered

  • Explaining inertia and constant velocity with Newton's First Law
  • Using F = ma to connect force, mass, and acceleration
  • Identifying action-reaction pairs on different interacting objects
  • Reading force diagrams and calculating net force and acceleration
  • Applying Newton's Laws to vehicles, sports, rockets, walking, and safety equipment

How to use these practice tests

First identify the object being analyzed and draw the forces acting on it. Add the forces with direction, decide whether the net force is zero, and then apply the appropriate Newton law or F = ma relationship.

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

Select a test

5 Tests
1. Test2. Test3. Test4. Test5. Test

3. Test

Grade 8 Newtons Laws Introduction Practice Tests

Practice Grade 8 Science questions about Newtons First, Second, and Third Laws, inertia, net force, acceleration, force pairs, diagrams, and applications.

Choose the best answer for each question. Identify the Newton law, track force directions and objects, and use F = ma when calculation is needed.

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

What does Newtons Third Law state?

Please select an answer first.

Correct answer: A

The correct answer is For every force, there is an equal and opposite force..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

Third Law forces occur in pairs between interacting objects and have equal size and opposite direction.

2. QuestionMultiple choice

Why does a swimmer move forward when pushing water backward?

Please select an answer first.

Correct answer: B

The correct answer is The water pushes the swimmer forward with an equal opposite force..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

The swimmers push on water and waters reaction force pushes the swimmer forward.

3. QuestionMultiple choice

When a bat hits a ball, which statement is correct?

Please select an answer first.

Correct answer: C

The correct answer is The bat and ball exert equal and opposite forces on each other..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

The interaction produces equal opposite forces on different objects, even if their accelerations differ.

4. QuestionMultiple choice

Why can a person move forward while walking?

Please select an answer first.

Correct answer: D

The correct answer is The foot pushes backward on the ground and the ground pushes forward on the foot..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

The foot-ground interaction creates an action-reaction pair that helps produce forward motion.

5. QuestionMultiple choice

Where do the forces in a Third Law pair act?

Please select an answer first.

Correct answer: A

The correct answer is On two different interacting objects.

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

Action-reaction forces are equal and opposite but act on different objects, so they do not cancel on one object.

6. QuestionMultiple choice

How does a rocket accelerate upward?

Please select an answer first.

Correct answer: B

The correct answer is The rocket pushes exhaust gases downward, and the gases push the rocket upward..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

The rocket and exhaust form an action-reaction pair.

7. QuestionMultiple choice

A book pushes down on a table. What is the reaction force?

Please select an answer first.

Correct answer: C

The correct answer is The table pushes upward on the book..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

The table and book exert equal opposite contact forces on each other.

8. QuestionMultiple choice

Why does a jumper push downward on the ground before moving upward?

Please select an answer first.

Correct answer: D

The correct answer is The ground pushes upward on the jumper in response to the downward force..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

The ground reaction force can accelerate the jumper upward.

9. QuestionMultiple choice

How do airbags reduce injury during a collision?

Please select an answer first.

Correct answer: A

The correct answer is They increase stopping time and can reduce the average force on the passenger..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

For a similar change in motion, a longer stopping time reduces average force.

10. QuestionMultiple choice

Why do Third Law forces not cancel the motion of one object?

Please select an answer first.

Correct answer: B

The correct answer is The paired forces act on different objects..

  1. Identify the law or force: Decide whether the situation demonstrates inertia, the force-mass-acceleration relationship, or an action-reaction pair.
  2. Track the objects and directions: List the forces, identify which object receives each force, and determine the net force and direction when needed.
  3. Apply the equation or model: Use F = ma, a force diagram, data, or a real-world example to check that the explanation matches Newton law.

Cancellation for net force is considered on one object, but an action-reaction pair acts across two objects.

Previous testNext test