Anurag Kishore
Last Activity: 13 Years ago
Hello
sn = u + a(2n-1)/2 ---------------------(1)
sn is distance covered in nth second
So, distance covered in (n-3)th second = a(2n-7)/2 = 5(2n-7) ---------------(2)
replacing n by (n-3) in equation (1)
here, u=0 and a=10
Also,
distance covered in (n-3) seconds = 1/2 a t2 = 5(n-3)2 -------------------------(3)
but according to quest.
5(n-3)2/5(2n-7) = 4/3
so, n = 5sec because 11/3 is not possible
So
H = 1/2 a n2 = 5*52 = 125metres
plz approve if u like the solution
Anurag Kishore