Motional emf problem on inclined plane

[yankans]

Homework Statement

a straight horizontal rod slides along parallel conducting rails at an angle with the horizontal of 30 degrees (inclined plane). The rails are connected at the bottom by a horizontal rail so that the rod and rails form a closed rectangular loop. A uniform vertical field exists throughout the region.
assume: rod remains in contact w/ rails as it slides down rails. rod experiences no friction/air drag. Rails and rod have negligible resistance. g = 9.8m/s^2.
a)if velocity of the rod is 4.6m/s, what is the current through the resistor? answer in mA.
b) what is the terminal velocity of the rod? (in m/s)

note: this is like a motional emf problem - the rod on rails
and
rod = 71 g in mass, moving at 4.6m/s
magnetic field = 0.16 straight down
resistor = 6.8 ohms

Homework Equations

F magnetic field = IBl where l is lowercase L, the width btwn rails
Emf = Blv
magnetic flux = Blx

The Attempt at a Solution

I honestly have no idea where to start this problem...

 

[Astronuc]

See if these help - http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magint.html

The conductor is moving with velocity v in a B field. Current is induced.

Also, there is a force on the conductor related to I x B.

 

[nlightner]

I would first break down the problem into smaller parts and analyze each part separately. Firstly, I would calculate the force of the magnetic field on the rod using the formula F = IBl. From the given information, I can calculate the value of B, the magnetic field, which is 0.16 T. I can also calculate the value of l, the width between the rails, using the given angle of 30 degrees and the mass of the rod. With these values, I can calculate the force of the magnetic field on the rod.

Next, I would use the formula for motional emf, Emf = Blv, to calculate the emf induced in the loop. This emf can also be seen as the voltage across the resistor, which can then be used to calculate the current through the resistor using Ohm's Law.

To determine the terminal velocity of the rod, I would use the equation for magnetic flux, Blx, where x is the distance that the rod has traveled along the rails. I would set this value equal to the motional emf calculated previously and solve for x. This would give me the distance that the rod needs to travel in order to reach its terminal velocity.

Finally, I would use the formula for acceleration, a = F/m, to calculate the acceleration of the rod. Knowing the acceleration and the initial velocity, I can use the equation v^2 = u^2 + 2as to calculate the terminal velocity of the rod.

In conclusion, this problem involves applying principles of magnetism, electromagnetism, and mechanics to calculate the current through a resistor and the terminal velocity of a rod sliding down an inclined plane.