Question

The force constant of a spring gun is $50$$N/m$. If a ball of $20$ g be shoot by the gun, so that its spring is compressed by $10cm$, the velocity of the ball is:

• A. $5$$m/s$
• B. $15$$m/s$
• C. $25$$m/s$
• D. $20$$m/s$

Answer 1

The correct option is A $5$$m/s$

$\frac{1}{2}{mv}^2=\frac{1}{2}{kx}^2$
$v=\sqrt{\frac{R}{m}}x$
$=\sqrt{\frac{50}{20\times {10}^{-3}}}(10\times {10}^{-2})$
$=50\times {10}^{-1}$
$=5m/s$