Now that we can describe how much something moved, we would like to describe how quickly it moved The faster it moves, the less time it takes (inversely proportional) So…if we compare displacement divided by time to displace, we have described how quickly it moved That takes too many words…let’s call it:
Velocity How quickly an object displaces The rate of change of position
Velocity describes how quickly something moves – we might even call it the rate of movement What if the rate of movement changes? We might say it’s speeding up or slowing down We need to be able to describe how quickly it’s speeding up or slowing down That takes too many words…let’s call it:
Acceleration How quickly an object is speeding up or slowing down How quickly the velocity is changing The rate of change of velocity
Free-Fall Motion Free-fall motion is a special case of constant acceleration Free-fall motion is straight-line motion with constant acceleration (due to gravity), but only if we ignore air resistance.