Question

a bullet of mass 10 g is fired at a speed of 500 ms from a gun of mass 5 of . what is the recoil velocity of the gun

Answer 1

there are some problems in the questions but if we take the unit of the mass of gun as kg which is not mentioned in the question. also the speed of the bullet should be written as 500ms^-1 or 500 m/s.

so, we have m¹v¹=m²v²

therefore, 0.01*500=5*v²

now, v²=5/5=1m/s

Answer 2

m(bullet) = 10 g = 10/1000 kg 

v(bullet) = 500 m/s 

M(gun) = 5kg

m(bullet) x v(bullet) = m(gun) x v(gun) 

10/1000 x 500 = 5 x (-v) 

v = - 1 m/s