What Force Does a Rod Experience in a Magnetic Field Setup?

[physicsdawg]

Homework Statement

Wut force will the rod that rests on the 2 parallell rails feel when the battery switch is closed
http://s336.photobucket.com/albums/n343/physicsdude69/?action=view&current=phys2.jpg

a. to the right
b. out of the page
c. to the left
d. into the page

Homework Equations

based on the principle of lenz's law

The Attempt at a Solution

i feel like b, to counter the into the page force , but I don't have really a great idea

 

[cryptoguy]

you're trying to find out the force on the rod. According to the right-hand rule, the force will be perpendicular to both the current and the magnetic field. Do you know which way the current is running? What is the direction of the field? Use the RHR.

 

[physicsdawg]

Then It will go to the right, away from the battery, correct?

With the right hand rule, fingers are straight and thumb is pointing away from fingers at a 90* angle. A line going directly from thefinger tips will be the direction of the magnetic field. A line coming straight out of your palm will be the vector of the charge (or the direction of the current). And thumb will be pointing in the direction of the force applied on that charge by a magnetic field.

 

[cryptoguy]

thats not the right-hand rule I learned... There's a few variations but here's the simplest one (imo). Thumb = current, fingers = magnetic field, palm = force.
There's also this one.
http://en.wikipedia.org/wiki/Fleming's_right_hand_rule

 

[physicsdawg]

is the answer correct?

 

[cryptoguy]

No it's not

 

[physicsdawg]

but by this I get the thumb to point out of page, the fingers to point to the right, and the force to point directly up...and I do not see up as a choice...aaah i can't conceptualize

 

[cryptoguy]

My bad, I kinda gave you the wrong link, try this http://en.wikipedia.org/wiki/Image:Rechte-hand-regel.jpg or the method I described
(the link i gave you was for induced currents)