PHYS 2211 Chapter 3: Continued
Document Summary
Velocity ~ rate of change of position; comparison of two positions. Instantaneous acceleration ~ what we use when time interval we use to calculate acceleration from position (or velocity) is very small compared to any times we want to pay attention to. Average acceleration = (how much did your velocity change?) / (how long did it take to make that change?: acceleration is vector as well. Uses angle brackets, < >, to indicate average just like we did for velocity. Dimensionality of acceleration: since it is ratio of velocity (dimensionality l/t) to time (dimensionality t) acceleration has dimensionality l/t2. Average acceleration tells us change in velocity over some time interval. When t is small enough, we identify acceleration at that (central) time as instantaneous acceleration and as derivative of velocity v is derivative of position instantaneous acceleration is second derivative of position. X acceleration is derivative of x- velocity: y acceleration is derivative of y- velocity.
