🟦 2.1 What is a moment?
Today we will learn one of the most important concepts we will need to solve Statics problems. It is a little abstract -- at least, more abstract than thinking about forces. For that reason, sometimes students are reluctant to engage with this new concept. So, I want to start this lesson by being crystal clear about one fact: you will have to use moments in almost every problem in this course.
Browse the flipbook for an introduction to this new idea. In the next few sections, we'll learn about two ways to think of moments:
the effect of a force at a (perpendicular) distance to an axis
the tendency of a body to rotate
Flipbook or Animation: Introduction to Moments
🟦 2.x Visualizing the rotation of a body about an axis
x pushpin analogy (or, using your left hand to hold a pen, which is the axis, and your right hand to figure out the sign)
🟦 2.x Translational Motion + Rotational Motion = MOTION
❏ Flipbook: x!)
🟦 2.x Moment as lever (types of levers)
Class 1: seesaw or pliers
Class 2: nutcracker
Class 3: tweezers
❏ Animation: Types of Levers
🟦 2.x Wait a minute - isn't this just torque (from Physics?)
In Physics, you learned that a torque is equal to the product of a force and a distance.
🟦 2.x Force couples (and explain why I always put "forces (and moments)" as a parenthetical note)
this is a super abstract concept so be super explicit here.
➜ Practice Problems
seesaws? lots of them?