A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 10.6 m/s. The cliff is 25 m above a flat, horizontal beach.

Question

A.) How long after being released does the stone strike the beach below the cliff? The acceleration of gravity is 9.8 m/s^2. Answer in units of s

B.) At impact, what is its speed? Answer in units of m/s

C.)At what angle below the horizontal does it land? Answer in units of ◦

Answer 1

A. d = Vo*t + 0.5g*t^2 = 25 m.
0 + 4.9t^2 = 25
t^2 = 5.10
Tf = 2.26 s. = Fall time. = Time in air.

B. V^2 = Vo^2 + 2g*d.
V^2 = 0 + 19.6*25.
V^2 = 490
V = 22.1 m/s.