Force constant of a weightless spring is `16 Nm^(-1)`. A body if mass 1 kg suspended from it is pulled down through 5 cm from its mean position and then released. The maximum kinetic energy of the body will be

Explanation

The fprce-sonstant of the spring is:
`k = F//y`
where F is the force producing an increase y in the length of the spring.
Here, `F = 1. 0 kg xx 10 N//kg = 10 N and `
`y =2 cm = 0.02 m`
`therefore k = (10N)/(0.02 m) = 500 N//m`
The period of oscillation of the body of mass m = `(1.0kg)` supended from the speing,
`T = 2pi sqrt ((m)/(k))`
`= 2 xx 3.14 xx sqrt ((1.0)/( 500 )) = 0.28s.`
The kinetic energy of oscillation of the spring is equal to word done in pulling the spring by 10 cm (0.1m). Thus kinetic energy.
`K = (1)/(2) kx ^(2) = (1)/(2) (5000) xx (0.1) ^(2) = 2.5 J`