Question

Q19. A stone is dropped from the top of a cliff and is found to travel 14.7 m in the last second

before it reaches the ground. Find the height of the cliff.(g= 9.8 m/s2

).​

Answer 1

Answer:

11.025 m

Explanation:

Given:

Initial Velocity (u) = 0 m/s (as it was dropped from rest)

Final Velocity (v) = 14.7 m/s

Acceleration (a) = g = 9.8 m/s²

To find:

Height of the cliff, i.e, displacement of the stone (s)

Method to find:

v² = u² + 2as

⇒ 14.7 * 14.7 = 0 + (9.8*9.8*s)

⇒ 216.09 = 19.6s

⇒ s = 216.09/19.6

⇒ s = 11.025 m

Hence, the height of the cliff is 11.025 m.