Here are some shutter speeds that will give you good starting points for stopping or freezing motion.
The speeds listed assume your subject almost fills the whole frame and is moving horizontally. If the subject you are trying to capture is moving in a diagonal motion or only fills about half or less of the frame then you can cut the speeds by about half.
|Subject||Est. Mph||Shutter Speed|
|Person Walking (Slow)||2||1/250|
|Person Walking (Fast)||3-4||1/500|
|Person Riding Bike||15||1/2000|
|Person Bike Racing||30||1/4000|
|Plane Take Off/Landing||125||1/8000|
Thank for reading