Question

A stone falls from a building and reaches the ground 2.5 seconds later. How high is the building ? (g = 9.8 m/s^2)​

Answer 1

Solution :-

During Downward Movement from rest, the Initial Velocity is u = 0

So the equation becomes:

H = (1 / 2) × g × t²

= (1 / 2) x 9.8 x 2.52

= 30.6 m

Answer 2

Hey Dear,

◆ Answer -

h = 30.625 m

● Explaination -

# Given -

t = 2.5 s

a = g

# Solution -

Here, the stone falls freely from the building under the effect of gravitational acceleration.

According to Newton's 2nd law of kinematics -

s = ut + ½ at²

Substitute u = 0, t = 2.5 s & a = 9.8 m/s²,

h = 0 × 2.5 + ½ × 9.8 × 2.5²

h = 30.625 m

Therefore, height of the building must be 30.625 m.

Thanks for asking..