In this graph, when is the magnitude of velocity greatest?

Question

a1234 · Answer

Do I have to find the slope along the curve (where the velocity may be greater than anywhere else)?

danjs · Answer

Right. The velocity remember is a change in position over a change in a time, like m/s

notice from this position vs time graph, that means velocity at a time t is the slope of the graph at any time t

danjs · Answer

look at section B.   The position does not change from t=6 to t=10s.  The velocity must be 0m/s. It did not move

a1234 · Answer

Yes, and from 0-6 and 10-18 seconds it had a slope of 1 and 1/2.

danjs · Answer

right those are linear portions of the graph and you can calculate the slope,  notice the negative for C
A -- 1 m/s
C -- (-1/2) m/s

danjs · Answer

the + and - mean the direction in this case in 1-D motion in a line. Away or Towards

a1234 · Answer

So do I set up a couple of tangent lines for the curve to find the velocity?

danjs · Answer

you could, simce the slopes (velocity) is changing, the thing is accelerating in that part D.

you can estimate the slope in D is larger than 1 from the last sectioon of it

danjs · Answer

It doesnt ask for a value, but you can say by looking that the slope at the end of D is the greatest, larger than for A--1

a1234 · Answer

That's true, it could be said by looking at the graph. There is a part of the assignment that asks for the calculations, so I'm going to graph it out.

Thanks for the help!