Dear Student,
If u1 and u2 are the initial velocities of the two bodies before the collision, the total momentum before the collision is
Pi=m1u1+m2u2
Let v be the common velocity of the two bodies after collision. Then the final mo-mentum after collision is,
pf=(m1+m2)v
From the law of conservation of momentum
Pi=Pf
m1u1+m2u2=(m1+m2)v
∴v = m1u1+m2u2(m1+m2) = 20×10+40×5/20+40 = 200+200/60=400/60=6.67 ms−1
∴ After collision, the combined velocity of both the masses is 6.67m/s.
,Regards.
HOPE THIS MIGHT HELP YOU, THANK YOU !!! :)