A stone is aimed at a cliff of height h with an initial speed of 62 m/s directed 45° above the horizontal, as shown in the Figure below. The stone strikes at A, 6.56 s after launching. What is the height of the cliff?

Question

Can someone please tell me which equation(s) I need to use for this?

Answer 1

Not knowing where A is, it is going to be general.

Break the initial velocity into vertical and horizontal components. Then, using those, and the time of flight, you have two equations which should solve the problem:
Horizontal
distance= vih*time
Vertical:
height= viv*time - 4.9 time^2