Induced emf between theh ends of an antenna

[mike1234]

Homework Statement

A car with a vertical radio antenna 85cm long drives due east 25 m/s. The Earth's magnetic field at this location has a magnitude of 5.9 * 10-5 T and points northward, 72 degrees below the horizontal. a) Is the top or the bottom of the antenna at the higher potential? b) Find the induced emf between the ends of the antenna

Homework Equations

E=Bvl

The Attempt at a Solution

I started with E=Bvl where E=5.9 *10-5T *(cos 18 or 108 not sure)* 25m/s * .85m and get a value of 1.19mV with cos 18. however not sure should I use 108 instead but don't know the reasoning help someone

 

[mike1234]

does no one know the answer to this question

 

[Doc Al]

Hint: To use that formula, you need the component of B perpendicular to the antenna.