Up to this point, we have modeled all objects we have looked at as point particles.\u00a0 Regardless of the actual extent of the particle, we have treated, boxes, balls, cars, people, even planets, as if they occupied a single point in space.\u00a0 We have been able to do this because how the mass of an object is distributed hasn\u2019t mattered in the scenarios we have previously examined.\u00a0 But there are obviously situations where the way the mass of an object is distributed does matter, influencing both how forces act on the object and the object\u2019s resulting motion.\u00a0 To look at these scenarios, we must start by introducing a new model which we can use to describe objects with more complicated motion.<\/p>\n
Though there are many ways in which we could choose to make an object more complicated, let\u2019s begin by treating extended objects as rigid bodies, which do not deform as they move.\u00a0 As an example, a pulley with a string running across it acts like a rigid body because it doesn\u2019t change its shape as it rotates about its axis.\u00a0 What our new model will allow us to do is to describe not just the translational motion of an object (which is what we have done up to now), but also how the object rotates about some axis.<\/p>\n\n\t\t\t Candela Citations<\/h3>\n\t\t\t\t\t