AP EAPCET 08-Jul-2022 Shift 1 Paper

When a spring is stretched from some initial extension xi to some final extension xf, then work done in stretching = change in potential energy of spring.
Work done, W=∆U
=‌

1

2

k(xf2−xi2)
Here, k=50N∕m,xf=60‌cm=60×10−2m
xi=50‌cm=50×10−2m
So, work done W=

1

2

×50[(60×10−2)2−(50×10−2)2]
⇒W=

1

2

×50×10−4(3600−2500)
=1.5J