A gun fires a bullet of mass `50 g` with a velociy of `30 m//s`. Due to this, the gun is pushed back with a velocity of `1 m//s`, then the mass of the gun is :

Options

A. 5.5 kg
B. 1.5 kg
C. 0.5 kg
D. 3.5 kg

Answer

B

Explanation

(b) If no external force acts upon a system of two (or more) bodies then the total momentum of the system remains constant.
Hence, momentum before collision = momentum after constant
`m_1 u_1 = m_2 v_2`
Given, `u_1 = 1 m//s, m_2 = 0.05 kg, v_2 -= 30 m//s`
`rArr m_1 xx 1 = 0.05 xx 30`
`rArr m_1 = 1.5 kg`.