A machine gun has a mass of 20 kg. The firing rate of 500 bullets per

1.	A machine gun has a mass of 20 kg. The firing rate of 500 bullets per second and mass of each bullet Is 20 g. If the speed of the bullets 500 ms-1. Find the force required to keep the gun in its position.
Answer» m_gun = 20 kg, m_b= 20 g v_gun = ? v_b = 500 ms^-1 From Law of conservation of momentum M_gun V_gun + m_b v_b = 0 ⇒ V_gun = - \(\frac {20 \times 10^{-3} \times 500}{20}\) = – 0.5^-1 ∴ Force required to hold its position F = m \(\frac{v-u}{t}\) = 20 × \(\frac{(0.5-0)}{(\frac{1} {500})s}\) = 5000 N.

A machine gun has a mass of 20 kg. The firing rate of 500 bullets per second and mass of each bullet Is 20 g. If the speed of the bullets 500 ms-1. Find the force required to keep the gun in its position.

Answer»

m_gun = 20 kg, m_b= 20 g

v_gun = ? v_b = 500 ms^-1

From Law of conservation of momentum

M_gun V_gun + m_b v_b = 0

⇒ V_gun = - \(\frac {20 \times 10^{-3} \times 500}{20}\)

= – 0.5^-1

∴ Force required to hold its position

F = m \(\frac{v-u}{t}\) = 20 × \(\frac{(0.5-0)}{(\frac{1} {500})s}\)

= 5000 N.