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A bullet of mass 50 g is fired from a gun of mass 4kg. If velocity of the bullet just after firing is 40ms-1, what is the recoil velocity of the gun? |
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Answer» ✯Required QUESTION:From a rifle of mass 4 kg, a BULLET of mass 50 g is FIRED with an initial velocity of 35 m/s. Calculate the initial recoil velocity of the rifle.✯To Find:what is the recoil velocity of the gun?✯Solution:Mass of the rifle (m1) = 4 kgMass of the bullet (m2) = 50 g = 0.05 kgRecoil velocity of the rifle = v1A bullet is fired with an initial velocity (v2) = 35 m/sInitially, the rifle is at rest.Thus, its initial velocity (v) = 0Total initial momentum of the rifle and bullet system⇒ (m1+m2) × v = 0The total momentum of the rifle and bullet system after firing= m1v1 + m2v2= (4 × v1 ) + (0.05 × 35)= 4v1 + 1.75According to the LAW of conservation of momentumTotal momentum after the firing = Total momentum before the firing4v1 + 1.75 = 0v1= -1.75 / 4v1 = – 0.4375 m/sThe negative sign indicates that the rifle recoils backwards with a velocity of 0.4375 m/s. |
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