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

2. 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

Which equation represents Newtons Second Law?

Please select an answer first.

Correct answer: A

The correct answer is F = ma.

  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.

Newton Second Law relates net force, mass, and acceleration with F = ma.

2. QuestionMultiple choice

A 4 kg cart experiences a net force of 20 N. What is its acceleration?

Please select an answer first.

Correct answer: B

The correct answer is 5 m/s².

  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.

Use a = F / m: 20 N divided by 4 kg equals 5 m/s².

3. QuestionMultiple choice

If the mass stays constant and net force doubles, what happens to acceleration?

Please select an answer first.

Correct answer: C

The correct answer is Acceleration doubles..

  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.

From F = ma, acceleration is directly proportional to net force when mass is constant.

4. QuestionMultiple choice

If the net force stays constant and mass doubles, what happens to acceleration?

Please select an answer first.

Correct answer: D

The correct answer is Acceleration is cut in half..

  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.

From a = F / m, doubling mass while keeping force constant reduces acceleration by half.

5. QuestionMultiple choice

In which direction does acceleration point?

Please select an answer first.

Correct answer: A

The correct answer is In the direction of the net 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.

Acceleration has the same direction as the net force.

6. QuestionMultiple choice

A box has 15 N east and 9 N west acting on it. What is the net force?

Please select an answer first.

Correct answer: B

The correct answer is 6 N east.

  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.

Opposite forces subtract, and the larger eastward force leaves 6 N east.

7. QuestionMultiple choice

Which unit is used for force in the equation F = ma?

Please select an answer first.

Correct answer: C

The correct answer is The newton.

  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.

A newton is equivalent to kg·m/s² and measures force.

8. QuestionMultiple choice

What relationship should appear on a graph of net force versus acceleration for a fixed mass?

Please select an answer first.

Correct answer: D

The correct answer is A straight-line relationship through the origin.

  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 fixed mass, F = ma means force is directly proportional to acceleration.

9. QuestionMultiple choice

What happens when the net force on an object is zero?

Please select an answer first.

Correct answer: A

The correct answer is The object has zero acceleration and keeps its current velocity..

  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.

Zero net force can mean rest or constant velocity, not necessarily that the object is stopped.

10. QuestionMultiple choice

Why does a loaded cart need more force than an empty cart to reach the same acceleration?

Please select an answer first.

Correct answer: B

The correct answer is The loaded cart has more mass and therefore more inertia..

  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 the same acceleration, F = ma requires greater force when mass is greater.

Previous testNext test