A steam of a liquid of density ρ flowing horizontally with speed v rushes out of a tube of radius r and hits a vertical wall nearly normally. Assuming that the liquid does not rebound from the wall, the force exerted on the wall by the impact of the liquid is given by
πrρv
πrρv2
πr2ρv
πr2ρv2
D.
πr2ρv2
Cross-sectional area A = πr2
Volume of liquid flowing per second = AV = πr2v
Mass of the liquid flowing out per second = πr2vρ
Initial momentum of liquid per second = mass of liquid flowing x speed of liquid
= πr2vρ x v = πr2v2ρ
Since the liquid does not rebound after impact, the momentum after impact is zero.
Therefore, the rate of change of momentum = πr2v2ρ
According to Newton's second law, the force exerted on wall = rate of change of momentum
= πr2ρv2