In this experiment a mass connected to a rotating drum is free to descend down to the floor. With energy conservation the following expression is found for inertia: I=mr2[2hgt21] This expression so useful that inertia of any object depends only on r,h and t. (please learn what those values are from your book.) Actually independent from the shape of the object we can determine its inertia by putting it on top of a drum to which a mass m is connected and free to descend. Our system somehow is a scale for rotational motion, due to the analogy between the linear and rotational motion: F=m,a=I, Q1. Why 2I2>I1 condition must be satisfied? Q2. Show the dimension analysis for inertia