What does constant acceleration mean?

ok I just confused myself. does constant acceleration mean that it doesn change or that it changes constantly?

Constant acceleration means that an object has a velocity that keeps changing constantly. The amount of acceleration is the same.

So, if a car had constant acceleration, and it starts moving from a stop (in which case, when stopped it had a velocity of 0) then say at:

1 sec after moving its going 2 miles an hour;
2 sec after moving its going 4 miles an hour;
3 sec after moving its going 6 miles an hour;
4 sec after moving its going 8 miles an hour;
and so on.

So the velocity (the speed of the car, in this case in miles an hour) is constantly changing (its going up)- but the amount of acceleration stays the same, at 2 miles a second, I.e its constant.

Hope that makes sense!

I ll simplyfy it

a particle has a velocity X...
now it is said to have a constant velocity A...
So the velocity of the particle is X+A in the first second and X+A+A in the second second and so on...
just that the addition in velocity is a constant...

Cinthia, The previous examples are correct, however, remember that acceleration is BOTH a velocity AND a direction. (Ignoring air resistance) a ball dropped off a cliff has a constant acceleration due to gravity and will keep falling faster until it hits the ground. ALSO, a race car going exactly 100 MPH on an exactly circular track is also undergoing constant acceleration because its Direction is constantly changing by the same amount.

^^^ In the case of the ball, its acceleration will stop if it reaches terminal velocity however.