Question

A toy gun uses a spring of force constant k. When charged before being triggered in the upward direction the spring is compressed by x. If the mass of the shot is m, on being triggered, it will go upto a height of :

• A. $\frac{k{x}^2}{2mg}$
• B. $\frac{k{x}^2}{mg}$
• C. $\frac{k^2{x}^2}{mg}$
• D. $\frac{x^2}{3kg}$

Answer 1

The correct option is A $\frac{k{x}^2}{2mg}$

Energy stored in spring = P.E of mass m

$mgh=\frac{1}{2}k{x}^2$

$h=\frac{k{x}^2}{2m}=\frac{k{x}^2}{2mg}$