. A package sitting on a shelf is knocked off. The velocity of the box just before it hits the floor is 8.5 m/s. Calculate the height of the shelf using;

Question

A displacement/velocity/acceleration equation

Conservation of energy

and hence show that these two methods produce the same answer.

Answer 1

(A) v=gt
t=v/g
h=gt²/2 =gv²/2g²=v²/2g
(B)
mv²/2 = mgh
h= v²/2g