20 J work is required to stretch a spring through 0.1 m. Find the force constant of the spring If the spring is further stretched through 0.1 m, calculate work done

Explanation

P.E. of spring when stretched through a distance 0.1 m
`U=W.D.=1/2K.x^(2)=20J or k=4000N/m`
when spring is fruther stretched through 0.1 m, then P.E. will be:
`U^(.)=1/2k(0.2)^(2)=80J`
`W.D.=U^(.)-U=80-20=60J`