AP Physics 1 Flashcards: Newtons Third Law

What this deck covers

This deck focuses on Newtons Third Law, giving you a quick way to review the definitions, rules, and examples that matter most for AP Physics 1.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Identify the action-reaction pair when a fish swims forward.

Answer: Fish exerts force on water; water exerts equal and opposite force on fish. Fish propulsion depends on reaction forces from displaced water.

Flashcard 2: Identify the force pair when a diver pushes off a diving board.

Answer: Diver exerts force on board; board exerts equal and opposite force on diver. Pushing off creates equal and opposite forces on both objects.

Flashcard 3: Identify the reaction force when a ball hits the ground.

Answer: The ground exerts an equal and opposite force on the ball. Newton's Third Law requires an equal and opposite reaction force.

Flashcard 4: Identify the action-reaction pair when a book rests on a table.

Answer: Book exerts force on table; table exerts equal and opposite force on book. Contact forces always occur in pairs on different objects.

Flashcard 5: Identify the action-reaction pair when a bat hits a ball.

Answer: Bat exerts force on ball; ball exerts equal and opposite force on bat. Impact forces always occur in equal and opposite pairs.

Flashcard 6: What force does the Earth exert on you according to Newton's Third Law?

Answer: An equal and opposite force to your gravitational pull on Earth. Gravitational forces are mutual between Earth and you.

Flashcard 7: Which force is greater in an action-reaction pair?

Answer: Both forces are equal in magnitude but opposite in direction. Newton's Third Law states forces are always equal in magnitude.

Flashcard 8: State whether action-reaction forces cancel each other out.

Answer: No, because they act on different objects. Forces act on different objects, so they cannot cancel each other.

Flashcard 9: What is the reaction force when a person punches a punching bag?

Answer: The punching bag exerts an equal and opposite force on the person. Impact forces always have equal and opposite reactions.

Flashcard 10: Which law explains the propulsion of a rocket in space?

Answer: Newton's Third Law of Motion. Rockets work by expelling mass and experiencing reaction forces.

Flashcard 11: What is the reaction force when a person stands on the ground?

Answer: The ground exerts an equal and opposite force upwards on the person. The normal force supports your weight against gravity.

Flashcard 12: What is the reaction force when a person jumps off a boat?

Answer: The boat exerts an equal and opposite force on the person. Jumping creates equal and opposite forces on both objects.

Flashcard 13: Define the term 'action force' in the context of Newton's Third Law.

Answer: The force exerted by the first object on the second object. The action force is the initial force applied in the interaction.

Flashcard 14: What is the reaction force when a person pushes a shopping cart?

Answer: The cart exerts an equal and opposite force on the person. All applied forces have equal and opposite reactions.

Flashcard 15: When you walk, what is the reaction force according to Newton's Third Law?

Answer: The ground pushes back with an equal and opposite force. Friction from ground propels you forward when walking.

Flashcard 16: Identify the action-reaction pair when a person paddles a canoe.

Answer: Paddle exerts force on water; water exerts equal and opposite force on paddle. Paddling works through action-reaction forces with water.

Flashcard 17: What is the reaction force when a bullet is fired from a gun?

Answer: The gun exerts an equal and opposite force on the bullet. The recoil force causes the gun to kick backward.

Flashcard 18: What is the reaction force when a baseball is caught by a glove?

Answer: The glove exerts an equal and opposite force on the baseball. Catching involves impact forces in opposite directions.

Flashcard 19: What is the reaction when a magnet attracts a metal object?

Answer: The object exerts an equal and opposite force on the magnet. Magnetic forces are mutual between interacting objects.

Flashcard 20: State the reaction force when a bird flaps its wings downward.

Answer: The air exerts an equal and opposite force upward on the bird. The reaction force from air provides lift for flight.

Flashcard 21: Identify the action-reaction pair when a balloon releases air.

Answer: Air exerts force on balloon; balloon exerts equal and opposite force on air. Expelled air creates thrust through Newton's Third Law.

Flashcard 22: What is the reaction force when a crane lifts a load upwards?

Answer: The load exerts an equal and opposite force downwards on the crane. Lifting forces have equal and opposite weight reactions.

Flashcard 23: What is the reaction force when a baseball is caught by a glove?

Answer: The glove exerts an equal and opposite force on the baseball. Catching involves impact forces in opposite directions.

Flashcard 24: What force does the Earth exert on you according to Newton's Third Law?

Answer: An equal and opposite force to your gravitational pull on Earth. Gravitational forces are mutual between Earth and you.

Flashcard 25: What is the reaction force when a hammer hits a nail?

Answer: The nail exerts an equal and opposite force on the hammer. Impact forces always create equal and opposite reactions.

Flashcard 26: Identify the action-reaction pair when a person claps their hands.

Answer: Hands exert force on each other and receive equal and opposite forces. Each hand experiences equal and opposite impact forces.

Flashcard 27: Which force is greater in an action-reaction pair?

Answer: Both forces are equal in magnitude but opposite in direction. Newton's Third Law states forces are always equal in magnitude.

Flashcard 28: What will happen if you push a wall with a force of 10 N?

Answer: The wall pushes back with a force of 10 N. Newton's Third Law guarantees an equal and opposite reaction force.

Flashcard 29: State whether action-reaction forces cancel each other out.

Answer: No, because they act on different objects. Forces act on different objects, so they cannot cancel each other.

Flashcard 30: Identify the action-reaction pair when a fish swims forward.

Answer: Fish exerts force on water; water exerts equal and opposite force on fish. Fish propulsion depends on reaction forces from displaced water.

Flashcard 31: What is the reaction force when a person leans on a wall?

Answer: The wall exerts an equal and opposite force on the person. All contact forces have equal and opposite reaction forces.

Flashcard 32: Identify the action-reaction pair when a person paddles a canoe.

Answer: Paddle exerts force on water; water exerts equal and opposite force on paddle. Paddling works through action-reaction forces with water.

Flashcard 33: What is the reaction force when a person punches a punching bag?

Answer: The punching bag exerts an equal and opposite force on the person. Impact forces always have equal and opposite reactions.

Flashcard 34: What is Newton's Third Law of Motion?

Answer: For every action, there is an equal and opposite reaction. This is the fundamental statement of Newton's Third Law.

Flashcard 35: What is the reaction force when a person leans on a wall?

Answer: The wall exerts an equal and opposite force on the person. All contact forces have equal and opposite reaction forces.

Flashcard 36: What is the reaction force when a hammer hits a nail?

Answer: The nail exerts an equal and opposite force on the hammer. Impact forces always create equal and opposite reactions.

Flashcard 37: When you walk, what is the reaction force according to Newton's Third Law?

Answer: The ground pushes back with an equal and opposite force. Friction from ground propels you forward when walking.

Flashcard 38: Identify the action-reaction pair when a horse pulls a cart.

Answer: Horse exerts force on cart; cart exerts equal and opposite force on horse. Pulling forces create equal and opposite tension forces.

Flashcard 39: Define the term 'action force' in the context of Newton's Third Law.

Answer: The force exerted by the first object on the second object. The action force is the initial force applied in the interaction.

Flashcard 40: When a swimmer pushes against the water, what is the reaction force?

Answer: The water pushes back against the swimmer. The reaction force from water propels the swimmer forward.

Flashcard 41: In which direction does the reaction force act compared to the action force?

Answer: Opposite direction. Action and reaction forces are always opposite in direction.

Flashcard 42: What is the reaction force when a car tire pushes backward on the road?

Answer: The road exerts an equal and opposite force forward on the tire. Friction from road provides the forward force on the car.

Flashcard 43: Identify the reaction force when a ball hits the ground.

Answer: The ground exerts an equal and opposite force on the ball. Newton's Third Law requires an equal and opposite reaction force.

Flashcard 44: When a swimmer pushes against the water, what is the reaction force?

Answer: The water pushes back against the swimmer. The reaction force from water propels the swimmer forward.

Flashcard 45: What is the reaction force when a person sits on a chair?

Answer: The chair exerts an equal and opposite force upwards on the person. The normal force balances the person's weight downward.

Flashcard 46: Identify the action-reaction pair when a person claps their hands.

Answer: Hands exert force on each other and receive equal and opposite forces. Each hand experiences equal and opposite impact forces.

Flashcard 47: What is Newton's Third Law of Motion?

Answer: For every action, there is an equal and opposite reaction. This is the fundamental statement of Newton's Third Law.

Flashcard 48: Identify the action-reaction pair when a balloon releases air.

Answer: Air exerts force on balloon; balloon exerts equal and opposite force on air. Expelled air creates thrust through Newton's Third Law.

Flashcard 49: What will happen if you push a wall with a force of 10 N?

Answer: The wall pushes back with a force of 10 N. Newton's Third Law guarantees an equal and opposite reaction force.

Flashcard 50: When a dog pulls on a leash, what is the reaction force?

Answer: The leash exerts an equal and opposite force on the dog. Tension forces always occur in equal and opposite pairs.

Flashcard 51: What happens to the forces when two objects interact according to Newton's Third Law?

Answer: They exert equal and opposite forces on each other. This is the fundamental principle of Newton's Third Law.

Flashcard 52: If a car accelerates forward, what is the reaction according to Newton's Third Law?

Answer: The road exerts an equal and opposite force backward on the car. The car pushes forward on road; road pushes backward on car.

Flashcard 53: When a dog pulls on a leash, what is the reaction force?

Answer: The leash exerts an equal and opposite force on the dog. Tension forces always occur in equal and opposite pairs.

Flashcard 54: Define the term 'reaction force' in the context of Newton's Third Law.

Answer: The force exerted by the second object back on the first object. The reaction force is always equal in magnitude to the action force.

Flashcard 55: Which law explains the propulsion of a rocket in space?

Answer: Newton's Third Law of Motion. Rockets work by expelling mass and experiencing reaction forces.

Flashcard 56: Identify the action-reaction pair when a book rests on a table.

Answer: Book exerts force on table; table exerts equal and opposite force on book. Contact forces always occur in pairs on different objects.

Flashcard 57: Identify the action-reaction pair when a rower rows a boat.

Answer: Oar exerts force on water; water exerts equal and opposite force on oar. Rowing uses action-reaction forces against water for propulsion.

Flashcard 58: What is the reaction when a magnet attracts a metal object?

Answer: The object exerts an equal and opposite force on the magnet. Magnetic forces are mutual between interacting objects.

Flashcard 59: In which direction does the reaction force act compared to the action force?

Answer: Opposite direction. Action and reaction forces are always opposite in direction.

Flashcard 60: Identify the force pair when a diver pushes off a diving board.

Answer: Diver exerts force on board; board exerts equal and opposite force on diver. Pushing off creates equal and opposite forces on both objects.

Flashcard 61: Identify the action-reaction pair when a horse pulls a cart.

Answer: Horse exerts force on cart; cart exerts equal and opposite force on horse. Pulling forces create equal and opposite tension forces.

Flashcard 62: What is the reaction force when a bullet is fired from a gun?

Answer: The gun exerts an equal and opposite force on the bullet. The recoil force causes the gun to kick backward.

Flashcard 63: What is the reaction force when a crane lifts a load upwards?

Answer: The load exerts an equal and opposite force downwards on the crane. Lifting forces have equal and opposite weight reactions.

Flashcard 64: What is the reaction force when a person stands on the ground?

Answer: The ground exerts an equal and opposite force upwards on the person. The normal force supports your weight against gravity.

Flashcard 65: What is the reaction force when a person jumps off a boat?

Answer: The boat exerts an equal and opposite force on the person. Jumping creates equal and opposite forces on both objects.

Flashcard 66: State the reaction force when a bird flaps its wings downward.

Answer: The air exerts an equal and opposite force upward on the bird. The reaction force from air provides lift for flight.

Flashcard 67: Describe the force interaction when two ice skaters push off each other.

Answer: Each skater exerts an equal and opposite force on the other. Newton's Third Law applies to all force interactions.

Flashcard 68: Define the term 'reaction force' in the context of Newton's Third Law.

Answer: The force exerted by the second object back on the first object. The reaction force is always equal in magnitude to the action force.

Flashcard 69: Describe the force interaction when two ice skaters push off each other.

Answer: Each skater exerts an equal and opposite force on the other. Newton's Third Law applies to all force interactions.

Flashcard 70: Identify the action-reaction pair when a rower rows a boat.

Answer: Oar exerts force on water; water exerts equal and opposite force on oar. Rowing uses action-reaction forces against water for propulsion.

Flashcard 71: What is the reaction force when a car tire pushes backward on the road?

Answer: The road exerts an equal and opposite force forward on the tire. Friction from road provides the forward force on the car.

Flashcard 72: What is the reaction force when a person sits on a chair?

Answer: The chair exerts an equal and opposite force upwards on the person. The normal force balances the person's weight downward.

Flashcard 73: What happens to the forces when two objects interact according to Newton's Third Law?

Answer: They exert equal and opposite forces on each other. This is the fundamental principle of Newton's Third Law.

Flashcard 74: What is the reaction force when a person pushes a shopping cart?

Answer: The cart exerts an equal and opposite force on the person. All applied forces have equal and opposite reactions.

Flashcard 75: Identify the action-reaction pair when a bat hits a ball.

Answer: Bat exerts force on ball; ball exerts equal and opposite force on bat. Impact forces always occur in equal and opposite pairs.