A thin 1.0-m rod pivoted at one end falls (rotates) frictionlessly from a vertical position, starting from rest. What is the angular speed of the rod when it is horizontal? [Hint: Consider the center of mass and use the conservation of mechanical energy.](adsbygoogle = window.adsbygoogle || []).push({});

So far I'm thinking that intial potential energy = final kinetic energy, so

mgh = K, where h = 0.5 m (the center of mass)

I can't seem to use K = 1/2 * I_{cm}* w^{2}+ 1/2 * M * v_{cm}^{2}

because I don't know v_{cm}... or can I find it?

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

Dismiss Notice

Join Physics Forums Today!

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

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

# Homework Help: Falling rod angular speed

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