Question

A ball is dropped from the top of a 91-m-high building. What speed does the ball have in falling 2.7 s?

Answer 1

Answer:

Let the speed of the ball is v.

Explanation:

we know that

v²=u²+2as

ball is dropped i.e means initial speed of the ball is 0.

now,

v²=0+2.a.s

v²=2x10x91

v=✓1820

v=42.66 m/s

but we have to calculate the speed at t=2.7s

as we know that t=✓(2h/g)

from here put t=2.7s

t².g=2h

(2.7)².10=2h

h= 36.45m

now speed at h=36.45m is

v²=2gh

v²=2.10.(36.45)

v²=729

v=27m/s

Answer 2

Answer:10.9 eq of kinamaticss

Explanation: