Question

A ball is dropped from a building.It travels 55 m during the last second of its fall.The time of fall and the height from which it falls?(g=10m/s^2)

Answer 1

Answer:

Explanation:

Thanks for asking this question.It can be done by using a simple formula as you can see in image. Hope it helps.

Answer 2

Answer:

6s, 180 m

Explanation:

sₙ = u + a/2(2n - 1)

Where n is total time for travel and sₙ is the displacement in n th second

Here,

sₙ = 55m

u = 0 (∵Ball is dropped from tower)

a = 10 m/s²

55 = 0 + 10/2(2n - 1)

55 = 10n - 5

6 = n

Hence, time for fall is 6 seconds.

s = ut + 1/2(at²)

s = 0 + 1/2(10)(6)(6)

= 180 m