Question

If the water falls from a dam into a turbine wheel 19.6m below, then the velocity of water at the turbine is? (g=9.8m/s)

(a) 9.8m/s

(b) 19.6m/s

(c) 39.2m/s

(d) 98m/s

This question was posed to me in semester exam.

I want to ask this question from Energy topic in section Kinematics of Engineering Physics I

Answer 1

Right option is (b) 19.6m/s

Easiest explanation: Loss in potential energy = Gain in kinetic energy

mgh = 1/2mv^2

v = √2gh = √(2×9.8×19.6)=19.6m/s.