1 The magnitude of a velocity vector is the rate of motion, usually measured in millimeters per year.  The direction of a velocity vector usually shows only the horizontal velocity. A vector is described in three dimensions: east-west, north-south, and up or down.
The cycle of eating and brushing can get tricky if you don't need to wait to eat after you brush, and then you brush after you eat -- over and over again during the day. If you eat sugary or acidic foods or drinks, the enamel on your teeth will be softened. Therefore, brushing right after you eat may not be wise. Dr. Rolfe explains that if you just had an acidic or sugary snack, you should gargle with a fluoride mouthwash and not brush your teeth.
Here's how: 1  Brush your teeth with fluoride toothpaste after every meal or at least twice a day. Bedtime is an important time to brush. 2  Brush up and down in a circular motion. 3  Gently brush your gums as well to keep them healthy. 4  Floss your teeth once a day to remove plaque and food that's stuck between your teeth.