Question 1: Define Newton's Third Law of Motion.

Answer: Newton's Third Law states that for every action, there is an equal and opposite reaction.

Question 2: Explain how action-reaction pairs act on different objects in a system.

Answer: Action-reaction pairs act on two different objects; one object's action force is met with an equal and opposite reaction force on the other object, ensuring the forces are paired but do not cancel each other out if acting on different objects.

Question 1: A boat of mass 2000 kg accelerates at 0.5 m/s² due to the force exerted by the water. What is the magnitude of the reaction force exerted by the boat on the water? (Use F = m × a)

Answer: 1000 N

Question 2: A person pushes a wall with a force of 50 N. What is the force exerted by the wall on the person? (State the principle involved)

Answer: 50 N, according to Newton's Third Law, the wall exerts an equal and opposite force.

Question 1: Describe a simple experimental setup to demonstrate action-reaction forces between two objects.

Answer: A suitable setup involves two carts placed on a frictionless surface connected with a force sensor. When one cart exerts a force on the other, both experience equal and opposite forces, illustrating Newton's Third Law. Safety precautions include ensuring the surface is clear of obstacles and using appropriate restraints to prevent carts from flying off.

Question 2: Identify two variables that should be kept constant during an experiment testing action-reaction forces.

Answer: Mass of the objects and the surface friction coefficient.

Question 1: A skateboarder pushes against a wall with a force of 150 N. The wall exerts a reaction force on the skateboarder. Describe the magnitude and direction of this reaction force and explain its effect on the skateboarder.

Answer: The reaction force is 150 N directed opposite to the skateboarder's push. It acts on the skateboarder, causing them to accelerate backwards if unrestrained, illustrating Newton's Third Law.

Question 2: In a scenario where a rocket expels gases downward with a force of 2,000,000 N, what is the equal and opposite reaction force exerted by the gases on the rocket? Explain how this force propels the rocket upward.

Answer: The reaction force is 2,000,000 N directed upward. This force propels the rocket upward as the expelled gases exert an equal and opposite force on it, in accordance with Newton's Third Law, generating thrust.

Question 1: Explain how the design of jet engines utilises the principle of action-reaction forces to produce thrust.

Answer: Jet engines expel exhaust gases at high speed backwards, exerting an equal and opposite reaction force that pushes the engine and aircraft forward, enabling flight.

Question 2: Describe how action-reaction forces are involved in the operation of a bicycle's brakes.

Answer: When the brake pads press against the wheel, the pads exert a force on the wheel, and the wheel exerts an equal and opposite force on the pads. This force slows the wheel's rotation, demonstrating action-reaction forces in braking.