Question

From a dam, water is pouring down at the rate of
150 kg/s, on the blades of a turbine. If a ball
dropped from the same dam takes 2 5 s to hit the
turbine, then the power delivered to the turbine is
approximately equal to (Take g = 10 m/s2)

Answer 1

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.