(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A small 1.25 kg ball on the end of a light rod is rotated in a horizontal circle of radius 0.890 m.

(a) Calculate the moment of inertia of the system about the axis of rotation.

____kg*m^2

(b) Calculate the torque needed to keep the ball rotating at constant angular velocity if air resistance exerts a force of 0.0800 N on the ball.

____m*N

2. Relevant equations

a) kg*m^2

b) kg*m^2-air resistance (dont know the formula; just a guess)

3. The attempt at a solution

a) 1.25*.89^2=.99kg*m^2 (i was able to figure out this answer)

b) 1.25*.89^2-.08=.91m*N

**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: Find torque of a ball on the end of a light rod

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