Physics Workout: Elevator and Counterweight “Classic” Problem 

In this video I demonstrate the power of the system schema when dealing with more than one moving object. The elevator and counterweight problem is based on the Atwood Device. Usually taught with systems of equations and some hand waving about direction... this approach allows you to conceptualize what is happening. This is a problem where two objects moving together as a system have the same amount of speed change every second, but they don’t have the same acceleration (the direction is different) ... crazy physics. The neat thing is that if you were to work the problem again but without idealization, you would already know the maximum value for the acceleration.