Q6. A hunter fires 50 g bullets from a machine gun. If each bullet moves with a velocity of 150 m/s how many such bullets are to be fired into a tiger of mass 60 kg coming towards him with a velocity of 10 m/s in order to stop the tiger?

 

Asked by sbidipak | 5th Jul, 2017, 07:25: PM

Expert Answer:

begin mathsize 12px style Let space straight n space be space the space number space of space bullets space each space of space mass space straight m space fired space with space straight a space velocity space straight v space towards space straight a space tiger space of space mass space straight M space moving space with space straight a space velocity space straight V. space
When space the space tiger space stops comma space applying space the space principle space of space conservation space of space linear space momentum space we space get
straight n space left parenthesis MV right parenthesis space plus space MV space equals space 0 space space space space space space open parentheses because space Final space Momentum space equals space 0 close parentheses
straight n space equals space fraction numerator negative space MV over denominator mv end fraction
Given space that space straight m space equals space 50 space straight g space equals space 50 space cross times space 10 to the power of negative 3 end exponent space kg
space space space space space space space space space space space space space space space space space space straight v space equals space 150 space straight m divided by straight s
space space space space space space space space space space space space space space space space space straight M space equals space 60 space kg space
space space space space space space space space space space space space space space space space space straight V space equals space minus space 10 space straight m divided by straight s
Substituting space the space values space in space the space above space equation space an space don space solving space the space value space of space straight n comma space we space get
straight n space equals space 80 end style

Answered by Yashvanti Jain | 6th Jul, 2017, 12:26: PM