Question

a bullet of 10g is fired from gun with muzzle velocity 200m/s find mass of gun if recoil velocity is _0.8m/s​

Answer 1

Explanation:

According to the law of conservation of momentum,

m¹u¹ + m²u² = m¹v¹ + m²v²(Not squared). ----(1)

Given, mass of bullet = 10g (i.e m¹ [let])

mass of gun = m² (let)

initial velocity of bullet (u¹) = 0 m/s (it is at rest)

initial velocity of gun (u²) = 0 m/s (it is at rest)

Final velocity of bullet (v¹)= 200 m/s

Final velocity of gun (v²)= -0.8 m/s (Due to recoil i.e in opposite direction)

Substituting the values in eq.(1) we get,

10×0 + m²×0 = 10×200 + m²×(-0.8)

0+0 = 2000 + -0.8m²

0.8m² = 2000

m² = 2000/0.8

m² = 2500g ≈2.5kg