The distance covers by a falling ball varies as the square of the time taken if a ball fall through 1800m I'm 15seconds. Calculate the distance when the time taken is 13second and the time taken for a distance of distance of 648m
Cutting through your bad grammar and bad spelling, I think I figured out what your question is.
you are saying: d = kt^2
when d = 1800, t = 15
1800 = k(15)^2
k = 8
so you have d = 8t^2 (not really true, but anyway.....)
when t = 13, d = 8(13)^2 = 1352
when d = 648
648 = 8t^2
t^2 = 81
t = 9