Answer:
Explanation:
For equilibrium
mg = kx ( restoring force of spring where k is force constant and x is stretch in it)
x = mg / k
= .5 x 9.8 / 40
= .1225 m
= 12.25 cm
b ) decrease in potential energy
= mgh
= .5 x 9.8 x .1225
= 0.6 J
c ) Energy stored in spring
= 1/2 k x²
= .5 x 40 x ( .1225 )²
= .3 J
It is 50% of gravitational potential energy lost
Rest of the energy might have lost in heating up the spring etc.