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A rifle of 3kg fires a bullet of 100 g at initial velocity of 30m/s calculat the initial recoil |
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Answer» Explanation: Mass of the rifle (m1) = 3 kg Mass of the bullet (m2) = 100g=0.1kg Recoil velocity of the rifle = v1 A bullet is fired with an initial velocity (v2) = 30 m/s Initially, the rifle is at rest. Thus, its initial velocity (v) = 0 The 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 = (3 × v1 ) + (0.1 × 30) = 3v1 + 3 According to the law of conservation of momentum Total momentum after the firing = Total momentum before the firing 3v1 + 3 = 0 v1= -3/3 v1 = -1 m/s The NEGATIVE SIGN indicates that the rifle RECOILS backwards with a velocity of 1 m/s. |
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