Question

A watermelon is dropped from the top of a 80m tall building. We want to find the velocity of the watermelon after it falls for 1.35s. We can ignore air resistance.
Kinematics formula would be most helpful to solve for the target unknown?

Answer choices in picture.

Answer 1

Answer:

$v_f = v_i + at$

$v_f = 13.23 m/s$

Explanation:

Height Of the watermelon when it is dropped is given as

$h = 80 m$

time of fall under gravity

$t = 1.35 s$

now if water melon start from rest then we have

$v_i = 0$

acceleration due to gravity for watermelon

$a = 9.81 m/s^2$

now we need to find the final speed of watermelon

$v_f = v_i + at$

so we will have

$v_f = 0 + (9.81)(1.35)$

$v_f = 13.23 m/s$