1.

A body falls from rest. In the last second of its fall, it covers half of the total distance then the total time of its fall is

Answer»

`(2-sqrt(2))s`
`(2+sqrt(2))`s
2 s
4s

Solution :Letbe total DISATNCE covered in n second
s/2 =0 +g/2(2n-1)
s=g(2n-1)=9.8(2n-1)
Also `s=0+(1)/(2)gn^(2)=4.9n^(2)`
`:. 9.8(2n-1)=4.9n^(2)`
or `n^2 -4n+2=0`
Solving the quadrtic EQUATION,
`n=(2+sqrt(2))` second.


Discussion

No Comment Found

Related InterviewSolutions