Question

Why is it difficult for a fireman to hold a hose, with ejects large amount of water at a high velocity ?

Answer 1

When fireman directs a large amount of water at a high velocity on fire from a hose pipe, they have to hold the hose pipe strongly because of its tendency to go backwards. The backward movement of the hose pipe is due to the backward reaction force of water rushing out through it in the forward direction at a high speed as per the Newton's third law of motion.