# M/s or m/s^2

1. Oct 20, 2007

### JBemp

Somewhere along the way i missed the diffrence between m/s and m/s^2 can someone please explain to me when i should use one or the other. i know there is some way to see it while working out the problem but is there any general rules or tips one could use as a guide line, my instructor say we will lose point on the exams is we answer with the wrong one.

2. Oct 20, 2007

### Staff: Mentor

m/s is simply speed or magnitude of velocity, which is the rate at which something moves or changes displacement or position. It is distance divided by time.

m/s2 = (m/s)/s is acceleration, or the rate at which speed or magnitude of velocity changes. As one accelerates, the speed increases, and as one decelerates, one slows or decreases speed.

m = meters, s = seconds, and they are part of the MKS or SI units system.

http://hyperphysics.phy-astr.gsu.edu/hbase/mot.html

http://hyperphysics.phy-astr.gsu.edu/hbase/units.html

Good luck and study hard.

3. Oct 20, 2007

### neutrino

m/s is the SI unit of velocity. m/s2 is the SI unit of acceleration.

The first is the rate of change of length per unit time, the other is the rate of change of the first with respect to time.

Your instructor is right in saying that. There is a reason why units and dimensions are always dealt with at the beginning of textbook/course. Using the wrong units may completely change the meaning of the answer, or, as in most cases, render your answer meaningless.