Question

A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then

• A. $mgh=\frac{1}{2}k{x}^2$
• B. $mg(h+x)=\frac{1}{2}k{x}^2$
• C. $mgh=\frac{1}{2}k(x+h{)}^2$
• D. $mg(h+x)=\frac{1}{2}k(x+h{)}^2$

Answer 1

The correct option is B $mg(h+x)=\frac{1}{2}k{x}^2$

Change in gravitational potential energy
= Elastic potential energy stored in compressed spring
$\Rightarrow mg(h+x)=\frac{1}{2}k{x}^2$