A 50kg rider on a moped of mass 75kg is traveling with a speed of 20 m/s. Each of the two wheels of the moped has a radius of 0.2m and a moment of inertia of 0.2 kg*m^2. What is the total rotaional kinetic energy of teh wheels?(adsbygoogle = window.adsbygoogle || []).push({});

KEr = 1/2Iw^2

= 1/2(.02)(20)^2

= 4

Two wheels = 2 *4 = 8 Joules

I think I am wrong as the angular velocity (w) has to be in rad/s. For some reason, I can not figure out how to get that. What is the formula for w?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: What is the total rotational kinetic energy of the wheels?

**Physics Forums | Science Articles, Homework Help, Discussion**