Question

You need to design an industrial turntable that is 45.0 cm in diameter and has a kinetic energy of 0.220 J when turning at 35.0 rpm (rev/min). A) What must be the moment of inertia of the turntable about the rotation axis? (in kg*m^2) B) If your workshop makes this turntable in the shape of a uniform solid disk, what must be its mass? (in kg)

Answer 1

a) Convert the units for the angular speed from rpm to rad/s. ω-35rpm 0.1047 rad/s -35 rpm lrpm) 3.6645 rad/s The rotational kinetic energy is Solve the equation for the moment of inertia of the turntable. 2K 2(0.220J) (3.6645 rad/s) -0.0327kg.m2

b) For a uniform circular disk the moment of inertia is solve the equation for the mass of the table-k IMR2 M 21 = R2 2(0.0327kg m2) 22.5×10-2 m = 1.29kg