# Forces exerted by a jet on numerical - Ishwaranand

## The forces exerted by a jet on a flat plate numerical Image Source ~ Crafted With ©Ishwaranand - 2020 ~ Image by ©Ishwaranand

Q.1) Determine the force exerted with a jet of water of diameter 75 mm at a stationary flat plate, if the jet strikes the plate commonly with a velocity of 20 m/s.
Given
• Diameter of nozzle, d = 75 mm = 0.075 m,
• Velocity of jet, V =20 m/s
Solution
• Area,
A = (π/4) d^2
A = (π/4) x (0.075)^2
A = 0.004417 m^2
F = ρAV^2
• where, ρ = 1000 kg/m3
F = 1000 x 0.004417 x 202 N
= 1766.8 N
=1.7668 kN

#### Q.2) Water is flowing through a pipe at the end of which a nozzle is fitted. The diameter of the nozzle is 100 mm and the head of water at the centre nozzle is 100 m. Determine the force exerted by the jet of water on a rigged vertical plate. All coefficient of velocity is given as 0.95.

Given
• Diameter of nozzle, d = 100 mm = 0.1 m,
• Head of water, H = 100 m,
• Co-efficient of velocity, Cv = 0.95
Solution
• Area of nozzle,
a = (π/4)d^2
=  (π/4) (0.1)^2
= 0.007854 m^2
Vth  = 44.294 m/s
• Actual velocity of jet of water,
V = Cv x Vth
V= 0.95 x 44.294
V= 42.08 m/s.
F = ρav2
= 1000 x 0.007854 x 42.082
= 13907.2 N
= 13.9 kN