# A stone is dropped from a tower at a height of h. Another stone is thrown at a height of 4h. Determine the time at which both the stones meet.

S1 = $frac{1}{2}gt^{2}$

S2 = $ut-frac{1}{2}gt^{2}$

S1 + S2 = h

4h = $frac{u^{2}}{2g}$

u = $sqrt{8gh}$

ut = h

$sqrt{8ght}$ = h

t = $sqrt{frac{h}{8g}}$