Which law describes what happens when the forces on an object are balanced?(1 point)

Question

Responses

Newton’s third law of motion
Newton’s third law of motion

Newton’s First Law of Motion
Newton’s First Law of Motion

The principle that rest is the natural state of objects.
The principle that rest is the natural state of objects.

Newton’s second law of motion

Which is an example of uniform motion, as used in Newton’s First Law?(1 point)
Responses

An air hockey puck slides across a table at constant speed.
An air hockey puck slides across a table at constant speed.

An air hockey puck slows when the air cushion is turned off.
An air hockey puck slows when the air cushion is turned off.

An air hockey puck bounces off a wall.
An air hockey puck bounces off a wall.

An air hockey puck accelerates when a player hits it.

Which law would be modeled by the image on the left?

Illustration of a person sitting in an ejector seat. In the first image the upward push of the chair and downward pull of gravity are equal, and the person is at rest. In the second image the upward push of the chair is greater than the downward pull of gravity, and the person accelerates upward?

Source: Ruth Thomlevold. NB Illustration. Pearson Education Ltd

(1 point)
Responses

Newton’s First Law
Newton’s First Law

Newton’s Third Law
Newton’s Third Law

Newton’s Second Law
Newton’s Second Law

Rest is the natural state of an object.
Rest is the natural state of an object.

The dogsled in the image moves at a constant speed in a straight line. Which of the following is true?

A team of dogs pulls a dogsled across level, snow-covered ground.

Source: Pi-Lens. Shutterstock

(1 point)
Responses

The backward pull of friction is smaller than the forward pull of the dogs.
The backward pull of friction is smaller than the forward pull of the dogs.

There is not enough information to answer the question.
There is not enough information to answer the question.

The forward pull of the dogs balances the backward pull of friction.
The forward pull of the dogs balances the backward pull of friction.

The backward pull of friction is larger than the forward pull of the dogs.
The backward pull of friction is larger than the forward pull of the dogs.

Carla demonstrates Newton’s First Law of Motion by slowly pushing a book across a table. The book moves at a constant rate of speed so long as she is pushing it. Which of the following is NOT true?(1 point)
Responses

There is an unbalanced force on the book, acting in the direction of motion.
There is an unbalanced force on the book, acting in the direction of motion.

The forces acting on the book are all balanced.
The forces acting on the book are all balanced.

The upward force exerted by the table balances the book’s weight.
The upward force exerted by the table balances the book’s weight.

Her push balances the force of friction.

Answer 1

Here are the answers to your questions based on Newton's laws of motion:

1. Which law describes what happens when the forces on an object are balanced?

   • Newton’s First Law of Motion (This law states that an object at rest stays at rest and an object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.)

2. Which is an example of uniform motion, as used in Newton’s First Law?

   • An air hockey puck slides across a table at constant speed. (This represents uniform motion since the puck is moving at a constant speed in a straight line.)

3. Which law would be modeled by the image on the left?

   • Newton’s Second Law (The description involves the relationship between the forces acting on the person in the ejector seat and their resulting motion. It shows how the acceleration is affected by the net force.)

4. The dogsled in the image moves at a constant speed in a straight line. Which of the following is true?

   • The forward pull of the dogs balances the backward pull of friction. (If the dogsled is moving at a constant speed, the forces are balanced.)

5. Carla demonstrates Newton’s First Law of Motion by slowly pushing a book across a table. The book moves at a constant rate of speed so long as she is pushing it. Which of the following is NOT true?

   • The forces acting on the book are all balanced. (Since Carla is applying a force to keep it moving, there is an unbalanced force acting on the book to overcome friction.)

These answers encapsulate the principles of Newtonian physics and how they apply to the scenarios presented.