Solving for the unknown variable in Motional EMF problem | Physics Homework

[flyingpig]

Homework Statement

http://img854.imageshack.us/img854/3980/33288207.th.png

Uploaded with ImageShack.us

The Attempt at a Solution

http://img813.imageshack.us/img813/1065/60582408.th.png

Uploaded with ImageShack.us

\varepsilon = IR

\varepsilon = -\frac{d \Phi}{dt}

\Phi = BA

-\frac{d \Phi}{dt} = -Bl\frac{dx}{dt} = -Blv

So

\frac{-Blv}{R} = I

\frac{-IR}{Bl} = v

Now I plug in and solve, is that right or did I underestimated this question completely?

 

[flyingpig]

Actually I just realize I assumed the current is running counter clockwise..

 

[flyingpig]

Actually never mind, by Lenz' Law the direction is counter clockwise for the current

 

[flyingpig]

Oh wait it says speed, so

\left | \frac{-lR}{Bl} \right | = |\vec{v}|

 

[flyingpig]

Please...I need mroe confidence.

 

[flyingpig]

I'll just trust myself...*crickets*

 

[SammyS]

Looks OK.

Your answer?

 

[flyingpig]

1m/s...