a) Find the moment of inertia of a point mass of 0.005 g at a perpendicular distance of 3 m from its axis of rotation. b) Find the moment of inertia of a sphere of mass 0.3 kg and radius 0.6 m. c) Find the kinetic energy of a rotating body with moment of inertia 0.003 kg m² and angular velocity of 0.6 rad s-¹.

A. 4.5 x 10^-5 kg.m2

B. 108 x 10^-3 kg.m2

C. 54 x 10^-5

Explanation:

A. I = m(r^2)

point mass m = 0.005 g = 5 x 10^-6 kg

I = (5 x 10^-6 kg) x (3 m)^2 = (5 x 10^-6 kg) x 9 m^2 = 4.5 x 10^-5 kg.m2

B. I = m(r^2)

point mass m = 0.3 kg = 3 x 10^-1 kg

I = (3 x 10^-1 kg) x (0.6 m)^2 = (3 x 10^-1 kg) x 0.36 m^2 = 108 x 10^-3 kg.m2

C. KE = 1/2I(w^2)

KE = 1/2(3 x 10^-2 kg.m^2)(0.6 rad/s)^2 = 54 x 10^-5

less than one you can't create energy

b.a device that inputs heat into a cool object