# How do I calculate the instantaneous velocity

1. Jan 26, 2005

### extreme

I've constructed a d-t graph and the question is, how do I calculate the instantaneous velocity, vinst, for each slope break? How do I find the slope break? Do I calculate it using v=chginx/chgint formed by the tangent line to the point or using the point alone simular to Vavg. I've drawn tangent lines to the peaks of the curves and computed rise over run with incorrect results.

2. Jan 26, 2005

### NateTG

Have you taken calculus, or do you know how to take derivatives?

3. Jan 26, 2005

### diegojco

vinst

you have the movement equation? if you have it and you have taken calculus you must know the vinst ist the first derivative of the function evaluated at the point you want to calculate vinst.

4. Feb 7, 2005

### extreme

Thanks. I was puzzled as to where to find the slope breaks. Once I graphed this out, I saw several linear lines that crossed each other along the graph and it was at these points I calculated Vinst.