Question

If the spring extended by $x$ on loading, then the energy stored by the spring is (If T is the tension in the spring):

• A. $\frac{T^2}{2x}$
• B. $\frac{T^2}{2k}$
• C. $\frac{2k}{T^2}$
• D. $\frac{2T^2}{k}$

Answer 1

Answer: (B)

$\frac{T^2}{2k}$

$U=\frac{1}{2}K{x}^2$ but $T=Kx$
So energy stored $=\frac{1}{2}\frac{(Kx{)}^2}{K}=\frac{1}{2}\frac{T^2}{K}$