Question

why are more firefighters needed to help hold the fire hose when the increase of water flow increases the force of the water? when the force of the water increases, the reaction force pushing the hose back decreases. when the force of the water increases, the reaction force pushing the hose back stays the same. when the force of the water increases, the reaction force pushing the hose back also increases.

Explanation:

According to Newton's third law of motion, for every action, there is an equal and opposite reaction. When the force of the water (action force) increases, the reaction force pushing the hose back also increases. So more firefighters are needed to hold the hose against the greater reaction force. The first option is wrong as reaction force should increase, not decrease. The second option is wrong as reaction force doesn't stay the same but changes with the action force.

Answer:

When the force of the water increases, the reaction force pushing the hose back also increases.