Question

When will an object dropped from rest attain a speed of 30 m/s?

Answer 1

Initial velocity = zero (i.e., free fall)

Final velocity = 30m/s

Acceleration due to gravity = 10m/s²

For a body falling freely under the action of gravity, g is taken positive
`.`

◈ First equation of kinenatics :

⇒ v = u + gt

⇒ 30 = 0 + 10t

⇒ t = 30/10

⇒ t = 3s

Hence, object will attain a speed of 30m/s after 3s.