Metalrod and magnetic field

[delta_simon]

Homework Statement

mass=m
length=l
initialspeed=v0
magneticfield=B
Resistor=R

Homework Equations

A metal rod of mass m and length l slides on two parallell frictionless rails.
A uniform magnetic field is directed perpendicular to the plane of the rails.
There is no external agent applying a force to the rod.

Show that v(t) = v0e^t/T
where T = mR/(Bl)²

The Attempt at a Solution

I don't know where to start. Shall I construct a differentialequation including dt and dA? If not the solution I would be greatful for some hints.

 

[siddharth]

I don't know where to start. Shall I construct a differentialequation including dt and dA? If not the solution I would be greatful for some hints.

Do you realize that there will be a motional emf developed? If find that, you'll be able to describe the motion of the metal rod.

This link should help
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elevol.html#c3