a machine gun bullet of mass m leaves a barrel at a speed of 250ms^-1

1.	a machine gun bullet of mass m leaves a barrel at a speed of 250ms^-1 and has a kinetic energy of 37500J. what is the mass of the bullets
Answer» $\underline{\underline{\Large{\bf Given:-}}}$ $\ast\sf Speed \:of\:bullet=v=250m/s$ $\ast\sf Kinetic\:energy=E_K=37500J$ $\underline{\underline{\Large{\bf To\:find:-}}}$ $\ast\sf Mass\:of\:bullet=m$ $\underline{\underline{\Large{\bf Solution:-}}}$ $\sf We\:know\:that$ $\boxed{\sf E_k=\dfrac{1}{2}mv^2}$ $\\ \sf\longmapsto 37500=\dfrac{1}{2}\times m\times 250^2$ $\\ \sf\longmapsto 37500=125^2m$ $\\ \sf\longmapsto 37500=15625m$ $\\ \sf\longmapsto m=\dfrac{37500}{15625}$ $\\ \sf\longmapsto m=2.4g$ $\\ \underline{\underline{\sf \therefore Mass\:of\:bullet\:is\:2.4g.}}$