During a science experiment, your teacher drops a tennis ball out of a window. The ball hits the ground 3 seconds later. (a) What was the ball's speed when it hit the ground? Ignore air resistance. (b) What was the ball's average speed during the 3 seconds? (c) How high was the window?

a) 29.43 m/s

b) 14.72 m/s

c) 44.15 m

Explanation:

For this question, apply free Fall formula

Given that a ball was dropped from a window and it took 3 seconds to hit ground, then;

a) speed of ball when it hit ground was;

v=gt where g is acceleration due to gravity and t is time the ball took to hit the ground

v = 9.81 * 3 = 29.43 m/s

b) Average speed = (initial velocity + final velocity) / 2

Initial velocity = 0m/s

Final velocity in 3 seconds = 29.43 m/s

Average speed = (0 + 29.43) / 2 = 14.72 m/s

c) Height of window is given by h=1/2 gt²

t=3s

g=9.81 m/s²

h=1/2*9.81*3² = 44.15 m