Question

question #1
what is the relationship between the force you apply to a heavy box and the force the box applies back to you?
a. the forces are equal in strength but act in the same direction.
b. the force you apply is stronger than the force the box applies back.
c. the forces are equal in strength but act in opposite directions.
d. the force the box applies back is stronger than the force you apply.
question #2
according to the text, what is a good example of force pairs in action?
a. a bird flying in the air.
b. a car driving down a road.
c. a person sitting on a chair.
d. a book lying on a table.
question #3
what is the main idea of newton’s third law of motion as explained in the text?
a. every action has an equal and opposite reaction.
b. objects at rest stay at rest, and objects in motion stay in motion.
c. force equals mass times acceleration.
d. the force of gravity pulls all objects towards the center of the earth.

Explanation:

Question #1

To solve this, we recall Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. When you apply a force to a box, the box applies a force back on you. These forces (action - reaction pair) should be equal in magnitude (strength) and opposite in direction. Option A says they act in the same direction, which is wrong. Option B and D suggest unequal forces, which violates Newton's Third Law. Option C correctly states the forces are equal in strength and act in opposite directions.

We need to identify a good example of force pairs (action - reaction pairs as per Newton's Third Law). Let's analyze each option:

• Option A: A bird flying - The bird pushes air down (action), and the air pushes the bird up (reaction). But let's check other options too.
• Option B: A car driving down a road - The main force here is the friction between the tires and the road, but it's not a clear - cut action - reaction pair example as the other options.
• Option C: A person sitting on a chair - The person exerts a downward force on the chair (action), and the chair exerts an upward normal force on the person (reaction). This is a direct action - reaction pair.
• Option D: A book lying on a table - The book exerts a downward force on the table (gravity - related), and the table exerts an upward normal force. But when considering "force pairs in action" (dynamic situation), a person sitting on a chair (where the action and reaction are more about the interaction between two bodies in a way that shows the force pair clearly) is a better example than a stationary book. However, let's re - evaluate. Wait, actually, for a person sitting on a chair, the action is the person's weight (force on chair) and the reaction is the normal force from chair to person. But a bird flying: the bird's wings push air down (action), air pushes wings up (reaction). But between the two (person sitting and bird flying), the person sitting is a more static - yet - clear example of an action - reaction pair. Wait, no, let's think again. The key is to find a pair of forces that are action - reaction. When a person sits on a chair, the person applies a force on the chair (action), and the chair applies a force on the person (reaction). This is a classic example. A bird flying: the bird's force on air and air's force on bird. But the options: let's check each. Option C: person sitting on chair - the forces are the person's weight (downward on chair) and the chair's normal force (upward on person) - action and reaction. Option A: bird flying - the bird and air. But the question is about "force pairs in action". A person sitting on a chair is a good example as the two forces (action and reaction) are clearly identifiable.

We need to find the main idea of Newton's Third Law of Motion. Let's recall the laws:

• Newton's First Law: Objects at rest stay at rest, and objects in motion stay in motion (Option B) - so B is for First Law.
• Newton's Second Law: Force equals mass times acceleration ($F = ma$) (Option C) - so C is for Second Law.
• Option D: Is about gravity, not Newton's Third Law.
• Newton's Third Law: Every action has an equal and opposite reaction (Option A).

Answer:

C. The forces are equal in strength but act in opposite directions.

Question #2