Exam 3 Physics Numbers 21-25

1. 21. Which are simultaneous equal but opposite forces resulting from the interaction of two objects?

A. net external forces

B. gravitational forces

C. field forces

D. action-reaction pairs

Action-reaction pairs are simultaneous equal but opposite forces resulting from the interaction of two objects. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object exerts an equal and opposite force on the first object. These pairs of forces are known as action-reaction pairs and are always present when two objects interact with each other.

Explanation

Action-reaction pairs are simultaneous equal but opposite forces resulting from the interaction of two objects. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object exerts an equal and opposite force on the first object. These pairs of forces are known as action-reaction pairs and are always present when two objects interact with each other.

2. 23. A hammer drives a nail into a piece of wood. Identify an action-reaction pair in this situation.

A. The nail exerts a force on the hammer; the hammer exerts a force on the wood.

B. The hammer exerts a force on the nail; the wood exerts a force on the nail.

C. The hammer exerts a force on the nail; the nail exerts a force on the hammer.

D. The hammer exerts a force on the nail; the hammer exerts a force on the wood.

When a hammer drives a nail into a piece of wood, the action-reaction pair can be identified as follows: the hammer exerts a force on the nail, and in response, the nail exerts an equal and opposite force on the hammer. This is an example of Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.

Explanation

When a hammer drives a nail into a piece of wood, the action-reaction pair can be identified as follows: the hammer exerts a force on the nail, and in response, the nail exerts an equal and opposite force on the hammer. This is an example of Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.

3. 22. Newton's third law of motion involves the interactions of

A. one object and one force

A. two objects and one force.

C. one object and two forces

D. two objects and two forces.

Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object exerts an equal and opposite force on the first object. Therefore, the interactions described in Newton's third law of motion involve two objects and two forces.

Explanation

Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object exerts an equal and opposite force on the first object. Therefore, the interactions described in Newton's third law of motion involve two objects and two forces.

4. 25. A batter strikes a baseball with a bat. Identify an action-reaction pair and describe the forces exerted by each.

A. The batter exerts a force on the bat; the ball exerts a force on the bat

B. The batter exerts a force on the bat; the bat exerts a force on the batter.

C. The bat exerts a force on the batter; the bat exerts a force on the ball.

D. The ball exerts a force on the bat; the bat exerts a force on the batter.

When a batter strikes a baseball with a bat, there is an action-reaction pair of forces involved. The batter exerts a force on the bat by swinging it, and at the same time, the bat exerts an equal and opposite force on the batter. This is known as Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. The force exerted by the batter on the bat and the force exerted by the bat on the batter are equal in magnitude but opposite in direction.

Explanation

When a batter strikes a baseball with a bat, there is an action-reaction pair of forces involved. The batter exerts a force on the bat by swinging it, and at the same time, the bat exerts an equal and opposite force on the batter. This is known as Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. The force exerted by the batter on the bat and the force exerted by the bat on the batter are equal in magnitude but opposite in direction.

5. 24. In an action-reaction pair, the

A. action force is exerted first.

B. action force and the reaction force are equal in magnitude and act in the same direction.

C. action force and the reaction force are contact forces only.

D. action force and the reaction force act on two different objects.

In an action-reaction pair, the action force and the reaction force are contact forces only. This means that both forces are exerted through direct contact between two objects. This is a fundamental principle in Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. The action force and the reaction force always occur simultaneously and are exerted on different objects. The magnitude of the forces is equal, but they act in opposite directions.

Explanation

In an action-reaction pair, the action force and the reaction force are contact forces only. This means that both forces are exerted through direct contact between two objects. This is a fundamental principle in Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. The action force and the reaction force always occur simultaneously and are exerted on different objects. The magnitude of the forces is equal, but they act in opposite directions.