A freely falling body, falling from a tower of heighth covers a distance h/2 in the last second of its motion The height of the tower is 10 `ms^(-2)`):

Options

A. 58 m
B. 50 m
C. 65 m
D. 60 m

Answer

a

Explanation

Let total time taken = nsecond.
`x_(nth) u+(1)/(2) a(2n-1)implies(h)/(2)=0+(1)/(2)g(2n-1)`
`implies h=g(2n-1)`
Also `h=ut+(1)/(2)gn^(2) implies h=0+(1)/(2) gn^(2)`
`:. (1)/(2)gn^(2)=g(2n-1) implies (1)/(2)n^(2)-2n +1=0`
`n^(2) -4n+2=0 implies n+(4pmsqrt(16-4xx1xx2))/(2xx1)`
Now `h=(1)/(2) gn^(2)=(1)/(2)xx10xx(3.414)^(2)=58 m`