Question

A bullet when fired at a target with a velocity of 100 m/sec penetrates one metre into it . if the bullet is fired at a similar target with a thickness 0.5 metre, then it will emerge from it with avelocity of___ m/s.

Answer 1

 the first case

a = (v2 - u2) / 2s

here,

u = 100m/s

s = 1m

v = 0

so,

a = (0 - 1002) / 2x1

thus,

a = -5000 m/s2

now,

in the second case

v = [u2 + 2as]1/2

here,

u = 100m/s

a = -5000 m/s2

and

s = 25cm = 0.25m

so,

v = [1002 + -(5000x0.25)]1/2

= [10000 - 1250]1/2

thus, emergent velocity will be

v = 93.541 m/s

Answer 2

Answer:

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