A body falls freely from rest. It covers as much distance in the last second of its motion as covered in the first three seconds. The body has fallen for a time of :

Options

A. 3 s
B. 5 s
C. 7 s
D. 9 s

Answer

B

Explanation

Let us assume the body falls for n seconds ` ," " (1)/(2) g (3)^(2) =(g)/(2) (2n-1) rArr n=5 s `