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A bullet of mass 10 g is fired from a gun of mass 6 kg with a velocity of 300 m/s. Calculate the recoil velocity of the gun. |
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Answer» Here, Mass of bullet=10 g =`10/100` kg =0.01 kg Velocity of bullet=300 m/s Mass of gun=6kg And, Recoil velocity of gun=? (To be calculated) Now, putting these values in the relation : Mass of bullet `xx`Velocity of bullet`xx`=mass of gun `xx`Recoil velocity of gun We get : `0.01xx300=6xx` Recoil velocity of gun So, Recoil velocity of gun=`(0.01xx300)/6` =0.5 m/s Note. The above prblem can also be solved by calculating the momentum of bullet and the gun separately as follows : Momentum of bullet=Mass of bullet`xx`Velocity of bullet `=0.01xx300` = 3 kg. m/s Now, suppose the recoil velocity of gun is v m/s. So, Momentum of gun=Mass`xx`Recoil velocity of gun `=6xx`v kg m/s According to the law of conservation of momentum : So, `3=6xxv` And, `v=3/6m//s` Recoil velocity of gun,v=0.5 m/s |
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