In your summer internship at GM, you are given the task of examining
the feasibility of a car powered by a rotating flywheel. The flywheel
is a composite ceramic material that can withstand accelerations up to
5000 g before breaking apart. The proposed flywheel is a solid disk
that is 1.2 m in diameter, 10 cm thick and has a mass of 250 kg.
The mass of the car without the flywheel is 850 kg. Engineering tests
have shown that a constant force of 150 N is needed overcome frictional
forces and maintain a constant vehicle speed of 60 mi/hr. To be marketable,
the car must be able to travel at least 50 miles without being re-spun.
What is the feasibility of this flywheel-powered car? How should
the flywheel be oriented in the "engine" compartment? How long will
it take to "charge" the car if a 5 HP electric motor is used? How
does the cost of electricity required to charge the car compare with the
cost of gasoline to provide a similar amount of energy? What advice
can you offer the design team of this flywheel-powered car?