A projectile of mass is fired horizontally from a spring gun that is initially at…

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

7. A projectile of mass

M_{1}

is fired horizontally from a spring gun that is initially at rest on a frictionless surface. The combined mass of the gun and projectile is

M_{2}

. If the kinetic energy of the projectile after firing is K, the gun will recoil with a kinetic energy equal to (A) K (B)

\frac{M_{2}}{M_{1}} K

(C)

\frac{M_{1}^{2}}{M_{2}^{2}} K

(D)

\frac{M_{1}}{M_{2}-M_{1}} K

(E)

\sqrt{\frac{M_{1}}{M_{2}-M_{1}}} K