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.
Most adults do not come close to brushing that long. To get a feel for the time involved, try using a stopwatch. To properly brush your teeth, use short, gentle strokes, paying extra attention to the gumline, hard-to-reach back teeth and areas around fillings, crowns or other restoration.Concentrate on thoroughly cleaning each section as follows:1  Clean the outer surfaces of your upper teeth, then your lower teeth.ost adults do not come close to brushing that long. These four steps are the best and easiest ways to help you remember how to care for your mouth, teeth and gums: Brush at least twice a day with fluoride toothpaste for at least two minutes, especially first thing in the morning and before bedtime.