Pulleys and belts. in a pulley system, pulley a is moving at 1500 rpm and has a diameter of 15 in. three pulleys, b, c, and d, all of different sizes, are attached to a single output axle. speed and torque output are changed within the system by moving the drive belt between pulleys b, c, and d.. 1.a speed of 1750 rpm is required when the drive belt is connected to pulley b. what is the diameter of pulley b? . 2.a speed of 2000 rpm is required when the drive belt is connected to pulley c. what is the diameter of pulley c? . 3.a speed of 3250 rpm is required when the drive belt is connected to?

For this question I would use the similarities between pulley A, to each pulley of the question. 

1. A speed of 1750 rpm is required when the drive belt is connected to pulley B. What is the diameter of pulley B?

15inches / 1500rpm = (x) inches / 1750rpm

(x)  = 15 inches * 1750 rpm / 1500rpm

(x) = 17.5 inches 

2.A speed of 2000 rpm is required when the drive belt is connected to pulley C. What is the diameter of pulley C?

15inches / 1500rpm = (x) inches / 2000rpm

(x)  = 15 inches * 2000 rpm / 1500rpm

(x) = 20 inches 

3. A speed of 3250 rpm is required when the drive belt is connected to?

15inches / 1500rpm = (x) inches / 3250rpm

(x)  = 15 inches * 3250 rpm / 1500rpm

(x) = 32.5 inches 

low freq = 100 mhz

low wavelength =101.7m

length = 3x10^8/freq

the higher the current the higher the mag field around it the higher the influence on the compass