Question

The work done in joules in increasing the extension of a spring of stiffness $10N/cm$ from $4cm$ to $6cm$.

• A. $1$
• B. $10$
• C. $50$
• D. $100$

Answer 1

The correct option is A $1$

Given Spring stiffness $K=10N/cm=1000N/m$, Initial Position $x_1=4cm=0.04m$, Final position $x_2=6cm=0.06m$

Work done by spring $=\frac{1}{2}K(x_2^2-x_1^2)$

$\Rightarrow \text{Work done}=\frac{1}{2}\times 1000\times ({0.06}^2-{0.04}^2)=1.0J$