Calculating speed needed to create motional EMF of given magnitude

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To create a 3.0 V motional EMF along a 1.2 m-long radio antenna, the necessary speed can be calculated using the relationship EMF = v * l * B, where v is velocity, l is the length of the antenna, and B is the magnetic field strength. The discussion highlights confusion regarding the variables involved, particularly how to determine the magnetic field strength (B) and area (A) for the calculation. It is noted that the length of the antenna corresponds to dx, but the time variable dt is unclear. Ultimately, the simple relationship EMF = v * l * B is emphasized as the key to solving the problem. Understanding this formula is essential for calculating the required speed to achieve the desired EMF.
Linus Pauling
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1. How fast would you have to drive your car to create a 3.0 V motional emf along your 1.2 m-long radio antenna? Assume that the motion of the antenna is perpendicular to B.



2. d(phi)/dt = EMF
dphi = B*A
v = dx/dt



3. I'm really not sure here. I think the length of the antenna will be dx, but I don't see how I'd get dt so solve for velocity. In a previous problem, worked out a minimum speed needed to create an EMF by using dphi = B*A = EMF*dt. But here I don't know B or A...
 
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Nevermind, I just overlooked the simple EMF = vlB relationship.
 

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