Given that,
Mass of body M=0.5kg
Potential energy P.E=100J
Force of gravity on 1 kg is 10 N
Now,
F=mg
10=1×g
g=10m/s2
Now, change in Potential energy
=mg(h2−h1)
=mg(h−0)
=mgh
Now, the height is
100=mgh
h=1000.5×10
h=20m
Hence, the height of the tower is 20 m