THE LEANING TOWER OF PISA IS 45m HIGH . A MASS OF 4kg IS DROPPED FROM TOP . CALCULATE :
a}THE POTENTIAL ENERGY AT THE TOP
b}THE KINETIC ENERGY JUST BEFORE HITTING THE GROUND
c}THE VELOCITY JUST BEFORE HOTTONG THE GROUND
Given - h=45m
m = 4 kg
Then PE= mgh
=4*45*9.8
= 1764 J
using law of conservation of energy
KE=1764 J
KE = 1/2 mv2
1764=1/2 * 4*v2
1764=2v2
882=v2
21root2 m/s
a) PE=1764J
b)KE= 1764 J
c)velocity just before hitting the ground=21root2 m/s