The spring is unstretched when $x=0.$ If the body

moves from the initial position $x_1=100mm$ to the

final position $x_2=200mm,(a)$ determine the work

done by the spring on the body,

$($b$)$ determine

the work done on the body by its weight, $($c$)$ determi$-$

ne the work by the frictional force and $($d$)$ determine

the total work.