Two particles are moving at a speed v such that they are always at a constant distance d apart and their velocities are always equal and opposite.at what time they return to their initial positions?

Answer 1

this is tricky. In my opinion, two object moving at the same and opposite direction means that both object traveled from a different point of origin. So if we have these objects stuck together because of the constant d, then i guess neither of the object will make it to the initial position.

in short, both object cannot get to the initial position.

Answer 2

The time should be 2πr/v

Answer 3

The time should be 2πr/v...as both the particles are at a constant distance d...therefore for one particle-
Distance covered =circumference
Velocity =v
Therefore..t=2πr/v