Question

A stone is dropped under gravity from rest from a height h and it travels a distance 18m in last second then time taken to come to ground is

Answer 1

Answer:

The last second then time taken to come to ground is 1.3 sec

Explanation:

Given:

For last second ,

time ,t= 1 sec

height ,h = 18 m

acceleration,a = 10 m/s^2

Then,

s=ut+1/2at^2

s= u x 1 +1/2 x 10 x(1)^2

18 = u + 5

u= 13m/s

This initial velocity ,u will be the final velocity at the last second .

Take 13 m/s as final velocity v' , then the initial velocity will be u'

v'=u'+at

13=0+10 x t

t=1.3sec

The last second then time taken to come to ground is 1.3 sec.

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