Question

Water from a fire hose is directed horizontally against a wall at a rate of 50.0 kg/s and aspeed of 42.0 m/s. Calculate the force exerted on the wall, assuming the water’s horizontalmomentum is reduced to zero.

Answer 1

Answer:

Explanation:

initial velocity, u = 42 m/s

mass per unit time, m = 50 kg/s

final velocity, v = 0

Force is equal to the rate of change of momentum

F = m ( v - u) / t

F = 50 x 42 = 2100 N

Answer 2

Answer:

magnitude of the force exerted on the wall is 2100 N.

Explanation:

given data

rate = 50.0 kg/s

speed = 42.0 m/s

solution

momentum is reduced = zero

so final speed v = 0

so relation between the force and the momentum is express as

Force =  $\dfrac{p}{t}$    ...............1

Force = $\dfrac{mv}{t}$    

put here value and we get

Force = $50 \times 42$  

Force = 2100 N

so that magnitude of the force exerted on the wall is 2100 N.