There must be some mistake in the printing of the book. It is supposed to be:
0.025v = 28
v = 1120 m/s
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
where does the 37 come from?
should have done better at school,,,,,,thanks p,