1. Acceleration

2. average acceleration The average acceleration of an object is defined ratiochange in velocity to be the ratio of its change in velocity to the time taken to change the velocity time taken to change the velocity. a av a av a av = average acceleration; m/s/s, mph/s, ft/s/s, km/hr/s in units of m/s/s, mph/s, ft/s/s, km/hr/s, etc... = v v v = change in velocity; m/s, in/s, ft/s, km/hr, mph in units of m/s, in/s, ft/s, km/hr, mph, etc... t t t = change in time; s, min, hr in units of s, min, hr, etc...

3. The “sign” of the acceleration indicates whether the velocity is increasing or decreasing.

4. positive sign A positive sign indicates that the velocity increasing increase in is increasing. It will also be an increase in speed positive speed if the object is traveling in the positive direction direction. It is a decrease in speed otherwise.

5. negative sign A negative sign indicates that the velocity decreasing decrease in is decreasing. It will also be a decrease in speed positive speed if the object is traveling in the positive direction direction. It is an increase in speed otherwise.

6. Constant v = v o + at x = v av t v av = (v + v 0 )/2 x = v o t + 0.5at 2 v 2 = v 0 2 + 2ax t = time x = displacement v 0 = initial velocity v av = average velocity a = acceleration v = final velocity