Question

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 940 rad/s. One such flywheel is a solid homogenous cylinder, rotating about its central axis, with a mass of 630 kg and a radius of 1.35 m. What is the kinetic energy of the flywheel after charging?

Answer 1

KE = 2.535 x 10⁷ Joules

Step-by-step explanation:

given,

angular speed of the fly wheel = 940 rad/s

mass of the cylinder = 630 Kg

radius = 1.35 m

KE of flywheel = ?

moment of inertia of the cylinder

`I = (1)/(2)mr^2`

=
`(1)/(2)* 630* 1.35^2`

= 574 kg m²

kinetic energy of the fly wheel

`KE = (1)/(2)I\omega^2`

`KE =(1)/(2)* 574* 940^2`

KE = 2.535 x 10⁷ Joules

the kinetic energy of the flywheel is equal to KE = 2.535 x 10⁷ Joules