Problem 29.25

In the figure, the rod moves to the right with a speed of 0.80 m/s and has a resistance of 2.2 2. The rail separation is l = 22.5

cm. The magnetic field is 0.37 T, and the resistance of the U-

shaped conductor is 24.5 at a given instant.

Part A

B (outward)

Calculate the induced emf.

Express your answer to two significant figures and include the appropriate units.

ANSWER:

e =

v dt

-dA/nPart B

Calculate the current in the U-shaped conductor.

Express your answer to two significant figures and include the appropriate units.

ANSWER:

I =/nPart C

Calculate the external force needed to keep the rod's velocity constant at that instant.

Express your answer to two significant figures and include the appropriate units.

ANSWER:

F =