Action and reaction: แบบฝึกหัด

When you press a light switch to turn on a lamp, what is the reaction force to your finger pushing the switch?

A book rests on a table. Which of the following statements correctly identifies the reaction force to the gravitational force exerted by the Earth on the book?

Consider a rocket accelerating upwards immediately after launch. If the upward thrust generated by the engine is \(T\) , the downward gravitational pull on the rocket is \(W\) , and the downward air resistance is \(R\) . Which of the following represents the actual action-reaction pair to the force that propels the rocket (the upward thrust \(T\) )?

When a swimmer performs a stroke, her hands push the water backwards. According to the principle of action and reaction, which force allows her to move forward through the pool?

According to Newton's Third Law of Motion, when a swimmer pushes water backward with her hands, what is the reaction force?

According to the principle of action and reaction, if a student pushes a wall with a horizontal force of \(50 \text{ N}\) to the left, what are the magnitude and direction of the reaction force exerted by the wall on the student's hand?

A stationary book rests on a table. According to Newton's Third Law, what is the reaction force to the force of the table pushing upwards on the book (the normal force)? Where does this reaction force act?

Explain why a rocket engine is able to produce thrust to change its velocity in the vacuum of outer space, where there is no air to push against, using the principle of action and reaction.

The principle of action and reaction is often observed in daily life, such as when someone jumps off a small boat.

a) When a person jumps forward from a small boat toward a pier, the boat is observed to move backwards. Explain this observation using the principle of action and reaction.

b) Clearly identify the action force and the reaction force in this specific interaction.

c) If the person pushes off the boat with a force of \( 120 \text{ N} \), what is the magnitude of the force that the boat exerts on the person?

A student of mass \(50 \text{ kg}\) stands on a stationary skateboard on a smooth, horizontal floor. He is initially positioned next to a heavy vertical wall. The student then uses his hands to push the wall horizontally with a force of \(80 \text{ N}\).