Читать книгу Physics I For Dummies - Steven Holzner - Страница 56

Acceleration is a measure of how quickly your velocity changes. When you pass a parking lot’s exit and hear squealing tires, you know what’s coming next — someone is accelerating to cut you off. After he passes, he slows down right in front of you, forcing you to hit your brakes to slow down yourself. Good thing you know all about physics.

You may think that, with all this speeding up and slowing down, you’d use terms like acceleration and deceleration. Well, physics has no use for the term deceleration, because deceleration is just a particular kind of acceleration — one in which speed reduces.

Like speed, acceleration takes many forms that affect your calculations in various physics situations. In different physics problems, you have to take into account the direction of the acceleration (whether the acceleration is positive or negative in a particular direction), whether it’s average or instantaneous, and whether it’s uniform or nonuniform. This section tells you more about acceleration and explores its various forms.