Question

A stone is dropped from a window that reaches ground in 0.5 seconds,what is the average speed during this time and calculate the height of the window from the ground​

Answer 1

Answer:

Initial speed (u) = 0  (as the stone is at rest)

Time = 0.5 seconds

Acceleration = 9.8m/s²

i) According to first equation of motion:

v = u + at

v = 0 + 9.8 x 0.5

v = 4.9 m/s

This is the speed just before stone hits the ground

ii) According to third equation of motion :

v² = u² + 2as

(4.9)² = 0 + 2 x 9.8 x s

24.01 = 19.6s

s = 1.225

so the average speed = 1.225/0.5 = 2.45m/s

iii) Height of window from the ground

Height = 1.225m

Explanation: