Collision of two charged particles projeced in magnetic field

[carlyn medona]

Homework Statement

Two particles having mass m separated by a distance d is uniform magnetic field as shown in the figure . If v=qBd/m, at what instant does collision occur. The coulomb force between the particles is switched off.

Homework Equations

T=2πm/qB

The Attempt at a Solution

For the given velocity each particle travel in a circle with radius d, at instant of collision each has completed 1/6 of it circular path, so I got time t=πm/3qB, but the solution says t=πm/6qB. Can somebody tell me where did I go wrong?

 

[berkeman]

Homework Statement

Two particles having mass m separated by a distance d is uniform magnetic field as shown in the figure . If v=qBd/m, at what instant does collision occur. The coulomb force between the particles is switched off.

Homework Equations

T=2πm/qB

The Attempt at a Solution

For the given velocity each particle travel in a circle with radius d, at instant of collision each has completed 1/6 of it circular path, so I got time t=πm/3qB, but the solution says t=πm/6qB. Can somebody tell me where did I go wrong?

Can you please Upload the figure -- it is difficult to tell what is going on. Can you also provide more details about the problem (charges?, Field direction?), and show your detailed work? Thank you.

 

[carlyn medona]

Sorry, I forgot that

 

[carlyn medona]

I actually solved it, they would collide when each particle has completed 1/12 of its circular path

 

[berkeman]

I actually solved it

Great, because I'm not very good at reading upside-down figures.