Question
The potential energy of a long spring when stretched by $2 \mathrm{~cm}$ is U. If the spring is stretched by $8 \mathrm{~cm}$, potential energy stored in it will be :
The potential energy of a long spring when stretched by $2 \mathrm{~cm}$ is U. If the spring is stretched by $8 \mathrm{~cm}$, potential energy stored in it will be :