Question

11. A ball is dropped from the height of 30 m. find time taken to fall through this height?​

Answer 1

Step-by-step explanation:

using Newton's second equation of motion

s=ut+1/2gt²

30=0+5t²

t=√6

t=2.44 seconds

Answer 2

ANSWER:

Initial velocity of the rock u=0

Final velocity of the rock when it reaches the ground v=30m/s

Using v

2

−u

2

=2aS where a=g=10m/s

2

∴ 30

2

−0

2

=2(10)H ⟹H=45 m