Question

A man release a stone at the top edge of a tower. During the last second of its travel,the stone fall through a distance of(9/25)H,where H is the tower’s height .Find H

Answer 1

equations of motion (EoM)

use EoM \(v^2 = u^2 + 2ax\) to establish velocities at positions shown in blue in drawing

from EoM \(v = u + at\) for final 1 second of flight time, we can say

\(v = u + g(1)\)

\(\sqrt{2gH} = \sqrt{2g \frac{16}{25}H} + g\)

then, solve for H [in terms of g]