Question

If rate of firing bullets of mass 20 gram from a machine gun in 360 bullets per minute and their speed is 3600 km/h, then what will be the force required to keep gun in position​

Answer 1

Rate of firing bullets of mass 20 gram from a machine gun in 360 bullets per minute and their speed is 3600 km/h.

• 3600 km/hr = 3600 × 5/18 = 1000 m/s

Force with which bullets are moving :

$F_{bullets} = \dfrac{\Delta P}{\Delta T}$

$\implies F_{bullets} = \dfrac{n \times (m\Delta v)}{\Delta T}$

$\implies F_{bullets} = \dfrac{360 \times \{\frac{20}{1000} \times (1000 - 0)}{60}$

$\implies F_{bullets} = \dfrac{360 \times 20}{60}$

$\implies F_{bullets} = 6 \times 20$

$\implies F_{bullets} = 120 \: N$

• So, force exerted by bullets towards gun is 120 N.

So, we need to hold the gun with 120 N to keep the gun in position.