Question

A 5.0 kilogram rock rolls off the edge of a cliff. If it is traveling at a speed of 24.2m/s when it hits the ground, what is the height of the cliff?

Answer 1

Using the kinematic equation ;

vf²=vi²+2ad just rearrange for d;

vf²-vi²=2ad;

(vf²-vi²)/2a=d

Now plug the numbers in.

vf=24.2

vi=0

a=9.81=g

(24.2²-0²)/(2*9.81)=29.8 m.