Question

A flywheel of moment of inertia 0.32 kg-m² is rotated steadily at $120 \mathrm { rad } / \mathrm { sec }$by a 50 W electric motor. The kinetic energy of the flywheel is

• A.
• B. 1152 J
• C. $2304 J$
• D.

Answer 1

Answer: (C)

$2304 J$

Answer 2

Kinetic energy $K _ { R } = \frac { 1 } { 2 } I \omega ^ { 2 }$ $= \frac { 1 } { 2 } ( 0.32 ) ( 120 ) ^ { 2 }$ = 2304 J.