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A bullet of mass 25g is fired horizontally from a rifle of mass 6kg. The bullet leaves the rifle with a speed of 500ms.
A) find, in ms, the initial speed of recoil of the rifle
The rifle recoils a horizontal distance of 2cm before coming to rest. Assuming that the horizontal force which brings it to rest is constant
B) find, in kN to 3 s.f, the magnitude of the horizontal force
{(mass of gun) + (mass of bullet)}x (velocity of bullet before fired) = (mass of gun x velocity of gun recoil) + ( mass of bullet x velocity of bullet fired)
{(6kg) + (0.025kg)} x (o m/s) = (6kg x velocity of gun fired) + ( 0.025 kg x 500m/s)
6.025kg x 0 m/s = {6kg x (velocity of gun recoil)} + 12.5 kgm/s
0kgm/s = {6kg x (velocity of gun fired)} + 12.5kgm/s
(velocity of gun recoil) = (0kgm/s -12.5kgm/s)/ 6kg
(velocity of gun recoil) = -12.5kgm/s / 6kg
(velocity of gun recoil) = 2.08 m/s
