Question

Explain why is it difficult for a Fireman to hold a hose, which ejects large amounts of water at high velocity.

Answer 1

Because according to newton's third law with whatever the momentum the water ejects the same momentum is created to the hose.
This is the reason that the fireman has to hold the hose strongly to overcome the momentum produced by the hose.

Hope u got that

Answer 2

Answer:

When a fire hose pipe ejects large amount of water in the forward direction at a high velocity, then the forward going stream of water exerts a backward reaction force due to which the hose pipe tends to go backward and slips from the hands of fireman. This backward movement of hose pipe makes it difficult for a Fireman to hold a hose pipe. And the Fireman has to hold the hose pipe strongly.