Question 8
A body of mass 20 kg moving with a velocity of 80 collides with another body of mass
30 kg moving with a velocity of 50 . If the two bodies moved together in the same direction after collision, find their common velocity if they moved in the:
(a) same direction before collision;
(b) opposite direction before collision.
Observation
The report by the chief Examiner indicated that most of the Candidates’ who attempted this question did very well.
In part (a), they were able to find that (20) (80) + (30)(50) = (20 + 30) v and solving for v yields v = 62ms-1.
In part (b), they also solved the equation (20) (80) – (30)(50) = (20 + 30) v to arrive at v = 2ms-1.