Question

From a dam, water is pouring down at the rate of 150kg/s, on the blades of a turbine. If a ball dropped from the same dam takes 2 under root 5 second to hit the turbine is aaproximately equal to (Take g = 10 m/s square) (1) 15w (2) 150kw (3) 125kw (4) 15.5kw

Answer 1

height of the dam s = 1/2 g t^2
s = 1/2 × 10×(2 sqrt(5))^2 = 100m.

Power in the water striking the turbines = m g h / time
P = 150 kg/s* 10 m/s^2* 100 m
= 150 kW

Answer 2

Hi friend,

Height of the dam=

S= ut + 1/2 g t²

Here initial velocity (u) = 0.

S= 0.5 × 10×(2√5)²

S= 100m.

power= potential energy / time

= mgh/time
= 150×10×200/2√5

= 15000 watt = 15kw. Hope this helped you a little!!!