Mechanical Design for the Stage

8

The Torque to Accelerate Mass, T_accel

Overview

In linear motion, all parts of an object, or put more specifically all of its component masses, are accelerated at the same rate. Mass in Newton’s second law, F = ma, is simply the mass of the object being moved, regardless of how that mass is distributed into, for instance, wagon structure, walls, props, or performers. When an object rotates however, the spacial distribution of mass relative to the axis of rotation has a major impact on the torque needed to accelerate it. Mass on or near the axis moves slowly compared with mass further out. A given angular acceleration on a compact, tight-to-the-axis piece will require much less torque than will a piece of the same mass that is much more spread ...