First slide
Work
Question

A Bullet when fired at a target has its velocity decreased to 50% after penetrating 30 cm into it.   Additional thickness  it will penetrate in cm before coming to rest is,

Moderate
Solution

    apply work energy theorem, work done = change in KE Let  F be resistive force, case 1:  F(30)  =   12m(V24-V2) ---(1) case 2:  F(30+x)  =   12m(0-V2) ---(2)  divide equation (1) by equation(2) 3030+x=34 x=10cm  _____1)
  
 

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