Answer:
The planets spun in epicycles.
Explanation:
The planets were not simply attached to a mystical sphere (“deferent”) but they were actually attached to a mini-sphere (“epicycle”) which rotated on the larger one.
To be able to answer this item, we are to calculate the power that the machine could deliver from hp to kW.
(45 hp)(746 W/1 hp) = 33570 W
Power is the amount of energy delivered at a certain period.
t = (6.20 x 10^2 J)/ (33570 kJ/s)
t = 0.01845 s
Velocity is distance over time

. If it wants it in km/h you're good to go otherwise if its m/s you need to convert km to m by multiplying 30 by 1000 and t in hours to seconds by multiplying 0.5 by 3600.
The answer of this question is B.