Answer:
<h2>
16,931 turns</h2>
Explanation:
The magnetic field produced is expressed using the formula
B is the magnetic field = 0.30T
I is the current produced in the coil = 4.5A
is the magnetic permittivity in vacuum = 1.26*10^-6Tm/A
L is the length of the solenoid = 32 cm = 0.32 m
N is the number of turns in the solenoid.
Making N the subject of the formula from the equation above;
Substituting the give values to get N;
The number of turns the solenoid must have is approximately 16,931 turns
Explanation:
We'll call the radius r and the diameter d:
We also assume that the riders are at a distance r = d/2 = 7m from the center of the wheel.
The period of the wheel is 24s. The tangent velocity of the wheel (and the riders) will be: (2pi/T)*r = 0.8 m/s (circa).
It means that in 3 minutes (180 seconds) they'll run 0.8 m/s * 180s = 144m.
Hopefully I understood the question. If yes, that's the answer.
