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# How to find the velocity and average speed from a displacement time graph? watch

1. I know to find the velocity it's just the gradient but the graph is like this:

*See screenshot.
(Well not exactly but hopefully you get what I mean)
Then how would I find the average speed? Would it just be the average speed for each section? So e.g 1st section average speed was 5 ms-1 for 10s and in 2nd section average speeed was 10ms-1 for 4s. Then: ((10*5)+(10*4)/9)?
Attached Images

2. velocity is the gradient on a displacement time graph

on a graph looking like like that there are times when v=0 (i.e. horizontal line)
there are times when v is +ve (i.e. +ve gradient / )
and times when v is -ve (i.e. -ve gradient \ )

speed is distance/time - you need to add up the total distances and divide by time.

distance isn't exactly the same thing as displacement

e.g. if I come out of my house, walk 100m to the bus stop, remember I've forgotten my sandwiches and walk 100m back to get them... at the point I arrive back at my house I've travelled a distance of 200m but my displacement from starting out is zero.

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Updated: October 16, 2017
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