Question

A bullet of mass 10gfired into wooden block mass 390g lying on smooth surface wood maves at a velocity of 10m/s.velocity of bullet

Answer 1

We know that
M1U1+M2U2=M1v1+M2v2.
by applying that we get
as initially bullet and wooden block are at rest and taking final velocity as v,
10g×0m/s+390g×0m/s =10g×v m/s+390g×10m/s .
0+0=10v +3900 a nd then...
-3900 g m/s
__________=v
10
-390 m/s .
-ve sign means moving in opposite direction.