Question

Water leaves the fireman's hose at rate of 7.2 kg/s and with a velocity of 21 m/s. Calculate the force exerted by the water jet on the wall of a building.

Answer 1

Splashing agaist the wall will reduce the water's forward momentum to zero. Ignore any backward momentum.

The force will be
momentum flow rate
= (mass flow rate) * V
It will be in Newtons

Answer 2

151.2