Answer:
2.05 m/s
Explanation:
Rotational kinetic energy is:
RE = ½ Iω²
Moment of inertia of a solid disk is I = ½ mr²:
RE = ½ (½ mr²) ω²
RE = ¼ mr²ω²
The tangential speed is v = ωr:
RE = ¼ mv²
Plug in values and solve:
0.21 J = ¼ (0.200 kg) v²
v = 2.05 m/s
