posted by Jasmine on .
A helicopter hovers above the north magnetic field pole in a magnetic filed of magnitude 0.5G perpendicular to the ground. The helicopter rotors are 10m long, are made of aluminum, and rotate about the hub with a rotational speed of 10 000 rpm. What is the potential difference form the hub of the to to the end?
I don't know what to do for this problem , what I first did was to transform rpm to m/s
2*pi*10m*10 000 rpm*(1min/60s)
and got 10742 m/s
I don't know where to go from there.
Eeach rotor=-d PHI/dt=-B*dA/dt
= 1E-4 tesla*PI*10^2/timeper revolution
what is the time per reveloution?
rpm to rps=10000/60
E=1E-4*PI*100*1E4/60=314/60 volt for each rotor, from center to end,so total EMF is twice that.