Movement

When you photograph a moving subject, you have two choices.
1. Still the movement to capture a moment in time
2. Show the subject moving and accept there will be some blurring. It gives the 'feeling' of movement

In the first one you need a fast shutter speed, how fast depends on the speed of the subject. A good starting point is 1/250. If there is still movement in your image, try a higher speed - 1/500 sec

To show movement - start at 1/15th sec and go slower to 1/4 or more to show more movement.

Evaluate your images. See how they make you feel!
Enjoy experimenting.