Question

Two coconuts fall freely from rest at the same time, one from a tree twice as high as the other. If the coconut from the shorter tree takes 2.0 s to reach the ground, how long will it take the other coconut to reach the ground?

Answer 1

Wee can use here kinematics

as we know that

$y = v*t + \frac{1}{2} at^2$

for shorter tree we know that

$y = 0 + \frac{1}{2}*9.8 * 2^2$

$y = 19.6 meter$

now since we know that other tree is twice high

So height of other tree is y = 39.2 m

now again by above equation

$y = v*t + \frac{1}{2} at^2$

$39.2 = 0 + \frac{1}{2}*9.8 * t^2$

$t = 2.83 s$

so the time taken is 2.83 s