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8. Problem 11.59P(HRW) Delivery trucks that operate by making use of energy stored
in a rotating flywheel have been used in Europe. The trucks are charged by using
an electric motor to get the flywheel up to its top speed of
What is the kinetic energy of the flywheel after charging? If the truck operates with an average power requirement of 8.0 kW, for how many minutes can it operate between chargings? |
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One such flywheel is a solid, homogeneous cylinder with a mass of
and a radius of
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Solution: Click For PDF Version (a) Flywheel is a rotating cylinder of mass M (500kg) and radius R
(1.0 m). Its rotational inertia I,
When the flywheel is rotating at its top speed
(b) By definition power is the energy delivered per second. Therefore, if the delivery truck operates with an average power of 8.0 kW, the charged flywheel will supply energy for time t,
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of
its
kinetic energy will be
