Question

A stone dropped into a well hits the water surface in 4 seconds. how deep is the well and with what velocity does the stone hit the water surface?

Answer 1

NLM 2nd {s=1/2at^2} u= 0 so putting value get ans as S=h= 78.4 m and velocity is get by NLM 3rd so v^2=u^2 + 2gs putting value we get ans u=0 compulserry ans is v=sruare root of 1536.64 m/s =39.2 m/s