14.3: Chapter 14 Homework Problems
Exercise \(\PageIndex{1}\)
A flywheel with a diameter of 2 ft and a weight of 60 lbs is rotating at a rate of 600 rpm. A brake applies a friction force to the outer rim of the flywheel, bringing it to a stop in 1.5 seconds. Based on this information, what was the average friction force applied by the brake over this time?
- Solution
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\(F_{brake} = 39.01 \ lbs\)
Exercise \(\PageIndex{2}\)
A ring-shaped space station can be approximated as a thin ring 60 meters in diameter with a mass of 500,000 kg. Centrifugal acceleration of the spinning station will be used to simulate gravity.
- To simulate the acceleration of Earth (9.81 m/s²), how fast will the station need to be spinning?
- If two thrusters each capable of exerting 10 kN of force will be used to get the station up to this speed, how long will we need to run the thrusters?
- Solution
-
\(\omega_f = 0.571 \ \frac{rad}{s}\)
\(t_{thrust} = 428.25 \ s\)