The wind blows a lawn chair that weighs 4 kg into a fence of 8 N. How much reaction force does the fence exert on the chair?

The reaction force exerted by the fence on the chair can be calculated using Newton's third law of motion, which states that every action has an equal and opposite reaction.

Since the force applied by the wind to the lawn chair is 8 N, the fence exerts an equal and opposite reaction force of 8 N on the chair.