Question

a ball is thrown with a speed of 3.0m/s horizontally from the top of a cliff 9.80 m high. Determine the time the ball is in the air before striking the ground.

Answer 1

The height at which the ball is thrown is given by

$$h = \frac {g t ^ {2}}{2} \gg t = \sqrt {\frac {2 h}{g}} = \sqrt {\frac {2 \cdot 9 . 8}{9 . 8}} = 1, 4 1 \mathrm {s}$$