Question

A boy on a 78.4m high cliff drops a stone. One second later, he throws another stone downwards with some speed. The two stones reach the ground simultaneously. Find the speed with which the second stone was thrown (Acceleration due to gravity=9.8 m/s2 ).

Answer 1

Answer:

42.9 m/s

Explanation:

v=d/t

v=78.4/x m/s

a=v/t

9.8=(78.4/x)/x

9.8=78.4/x^2

x^2=8

/(x^2=/(8

x=2.83 s

v=78.4/1.83

v=42.9 m/s

Hope this helps you☺................