Question

A particle is dropped from a building. It takes 4 sec for the particle to reach the ground. The
height of the building is

a) 20 m
b) 40 m
c) 80 m
d) 75 m​

Answer 1

Answer:

80m

Explanation:

s=1/2gt²(as the particle is dropped u=0)

s=1/2×10×4²

=80

Answer 2

Answer:

80 m

Explanation:          

dropped from a building means freely falling body

therefore initial velocity =0

we know that

S=ut+1/2gt²

S=0+1/2×10×4²

S=1/2×10×16

S=80 m