Final answer:
Newton's third law is exemplified in a trebuchet by the counterweight dropping and exerting a downward force, producing an equal and opposite reaction force that propels the projectile upward and forward, similar to thrust in rockets.
Step-by-step explanation:
An example of Newton's third law applied to a trebuchet would involve the counterweight and the projectile. When the trebuchet is triggered, the counterweight is dropped, exerting a force downwards due to gravity.
According to Newton's third law, there is an equal and opposite reaction force, which in this case is directed upward and propels the projectile forward. Much like the thrust in rockets, which propels them forward by expelling gas backward, the trebuchet launches the projectile due to the reaction force of the falling counterweight.
Reaction forces are evident in everyday life, whether it's a professor walking and pushing back on the floor or a car's wheels pushing back on the ground to move forward. Similarly, in a trebuchet, the counterweight exerts a force downward, and the trebuchet exerts an equal force upward on the projectile, sending it flying through the air.