Question

A machine gun fires 20grm bullet at the rate of 10 per sec with the speed of 500 m/sec if the mass of the gun is 10kg the force requierd to holdbthe gun in position

Answer 1

I am not a physicist but I know ot would be very little. An AR fires a ~60g bullet at ~1000 meters per second. Even at 400 rounds per minute the recoil is easily manageable if maybe hard to aim. The force required to hold the rifle you have stated would take about 1/12 the energy of a military full auto AR variant. There is just too much physics and vagueness in the gun described to make an accurate estimate.