Understanding Acceleration: Can It Be a Change in Speed or Direction?

[wakejosh]

ok, so since velocity has two parts, speed and direction, and since acceleration is defined as a change in velocity, can acceleration be either a change in speed or a change in direction?

 

[billiards]

a change in direction is always an acceleration. A change in speed is always an acceleration.

If one (or both) of those things is changing then there is an acceleration.

 

[radou]

ok, so since velocity has two parts, speed and direction, and since acceleration is defined as a change in velocity, can acceleration be either a change in speed or a change in direction?

Take a look at this, specially at paragraph #3: http://www.math.lsa.umich.edu/~glarose/classes/calcIII/web/14_4/" .