acceleration decrease(減加度速) 等唔等於 deceleration(負向加速)??
2006-12-23 18:38:43 · 3 個解答 · 發問者 harry 1 in 科學 ➔ 其他:科學
acceleration 是加速度,一般指物件以每秒計的時間加速移動,加速度下降(acceleration decrease)是物件每秒加速慢下來,即是還在加速。
deceleation是減速,指物件不但沒有加速,相反在減速。
所以,acceleration decrease 不等於 deceleration。
2006-12-23 18:49:11 · answer #1 · answered by cyril 6 · 0⤊ 0⤋
要明白什麼叫accleration 即加速率, 首先要知accleration其實係一個vector
First
Vector, 係乜黎呢?
係有方向性的,呢個好重要
Then
GIVE you an example
你係條路上面加速向左行,咁你的acceleration係正定係負呢
Ans: 不是正也不是負
因為acceleration係vector, 你要定義左邊個方向係正先
例如,如果我定義剛剛那個situation, i let left direction as positive
hence a is positive, that mean it carry out positive acceleration or negative deceleration
but if i let right direction as negative
a is negative, that mean it carry out positive deceleration or negative acceleration
2006-12-23 21:55:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
If you look on the physics point of view, the definition of acceleration is
acceleration = (final velocity - initial velocity)/time taken
In [acceleration decrease], the final velocity is still greater than the initial velocity, though the difference becomes smaller than before. That is, the magnitude of the acceleration is still positvie.
In [decceleration], or sometimes called retardation, the final velocity is smaller than the initial velocity, i.e. the difference of (final velocity - initial velocity) is negative and thus the magnitude of acceleration (i.e. decceleration) is negative.
Hence, acceleration decrease and decceleration means differently in physics.
2006-12-23 20:18:14 · answer #3 · answered by 天同 7 · 0⤊ 0⤋