Answer:
1 m/s
Explanation:
Using law of conservation of momentum
m1v1 + m2v2 = (m1 + m2)vf , where
m1 = mass of object at rest, 20 kg
v1 = initial velocity of object at rest, 0 m/s
vf = final velocity of the bodies
m2 = mass of object in motion, 10 kg
v2 = initial velocity of object in motion, 3 m/s
On substituting, we have
(20 * 0) + (10 * 3) = (20 + 10) vf
0 + 30 = 30 vf
vf = 30 / 30
vf = 1 m/s
Therefore, the velocity of the bodies after hitting each other is 1 m/s