Acar is designed to get its energy from a rotating flywheel in the shape of a uniform, solid disk of radius 0.600 m and mass 540 kg. before a trip, the flywheel is attached to an electric motor, which brings the flywheel's rotational speed up to 5.10 ✕ 103 rev/min.
(a) find the kinetic energy stored in the flywheel.

13.86 MJ

Explanation:

Since flywheel is a solid disk, its moment of inertia can be calculated with the following formula:

where m = 540kg is the mass and r = 0.6m is the radius

(a) the kinetic energy stored in the flywheel can be calculated

or 13.86 MJ

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.