First slide
Collisions
Question

Particle A collides elastically (perfect) with another particle B which was at rest. They disperse in opposite directions with same speeds. Ratio of their masses respectively must be

Moderate
Solution

From Law of conservation of linear momentum
m1v1+0=m1v+m2v
v=m1v1m2m1...1
Applying conservation of kinetic energy
12m1v12+0=12m1v2+12m2v2 … (2)
Solving (1) and (2) we get  m1:m2=1:3
Therefore, the correct answer is (B).
 

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App