There must be some mistake in the printing of the book. It is supposed to be:

0.025v = 28

v = 1120 m/s

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- Nov 2nd 2010, 03:54 AM #1

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## could somebody help me with this please

A gun of mass 3.5kg fires a bullet of 25g. the gun recoils at a speed of 8m/s-1, Calculate the velocity of the bullet.

total momentum before explosion=0

therefore total momentum after exposion=o

the book shows: m1 v1 + m2 v2,,,,,,, mass1 x velocity1 + mass2 x velocity2 ?

3.5x(-8)+0.025 v2 =0

-28+0.025 v2 =0

0.025 v2=37

v2=37/0.025 =1480m/s-1

where does the 37 come from?

should have done better at school,,,,,,thanks p,

- Nov 2nd 2010, 03:57 AM #2

- Nov 2nd 2010, 12:17 PM #3

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- Sep 2010
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- Nov 2nd 2010, 09:50 PM #4