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A bullet of mass 40 g is fixed from a rifel of mass 4 kg if its speed is increased from rest to 50m/s un 10 s calculate the amount of foece exerted |
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Answer» Answer:Mass of the rifle (m1) = 4 kg Mass of the BULLET (m2) = 50 g = 0.05 kg Recoil VELOCITY of the rifle = v1 A bullet is FIRED with an initial velocity (v2) = 35 m/s Initially, the rifle is at rest. Thus, its initial velocity (v) = 0 Total initial momentum of the rifle and bullet SYSTEM ⇒ (m1+m2) × v = 0 The total momentum of the rifle and bullet system after firing = m1v1 + m2v2 = (4 × v1 ) + (0.05 × 35) = 4v1 + 1.75 According to the law of conservation of momentum Total momentum after the firing = Total momentum before the firing 4v1 + 1.75 = 0 v1= -1.75 / 4 v1 = – 0.4375 m/s The negative sign indicates that the rifle recoils BACKWARDS with a velocity of 0.437m/s |
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