A ball is dropped from the rest from a high window of a tall building and called for 4 seconds. Neglecting air resistance, the final velocity of the ball is m/s. (g=-9.8m/s^2)

-39.2m/s

Explanation:

Given that :

t = 4secs

g = -9.8m/s^2

v = ?

u = 0m/s ( since it was at rest )

V = u +at 1

Where v is the final velocity

a = -g = -9.8m/s^2 since the ball was dropped from a height which will eventually make it move against gravity

t = 4secs

Substitute the values into 1

v = 0 - 9.8×4

v = -39.2m/s

he kicked it 10 feet straight up into the air? i think this works.

the part of the wave he is travelling on is the crest