Question

A stone dropped from a certain height takes 4 second to reach the ground. The height is​

Answer 1

Answer:

A. 19.6m

B. 39.2m

C. 156.8m

D. 78.4m

let the leight be H

Time taken = t = 4 seconds

initival velocity = u = 0

Acceleration = a = 9 =9.8ms^-2

now,

S = ut +1/2 at^2

H =0+1/2*9.8*4^2

H =78.4m

Hence,option D is correct