# Mr Usain Bolt 200m

1. Oct 21, 2009

### Nazz_Designs

I am looking for a graph of velocity vs time for the 200m race of Mr Usain Bolt which he did in 19.30 seconds he did during the olympic races.
I appreciate if someone can provide it in this forum.
Thanks

Ps. sorry if i posted it in the wrong place, but i dont in which category i should put it.

2. Oct 21, 2009

### Bob_for_short

It should be something like this:

|.................................................................
|......
|...
|.______________________________________|___

3. Oct 21, 2009

### Nazz_Designs

yes, i know the shape.

But during class we had a question which involved the graph.

my professor said that he thinks that the graph is not wrong.
and he told us if anyone can deduct what he thinks the problem is.
he told us if we can, we should find the original graph published.

hope you can help me from the attachment graph.

4. Oct 21, 2009

### Molydood

I used to run the bend in the 4x100 and although it feels faster, it isn't as quick as running in a straight line. Having said that it is unlikely that he will be able accelerate once he is onto the straight due to muscle fatigue. Top speed is likely to occur somewhere between 60m and 80m.

5. Oct 21, 2009

### Bob_for_short

Suppose that during acceleration period he had a constant acceleration a for t1 seconds. He reached the velocity v1=a*t1. He arrived at coordinate L1= at12/2. Then he ran with v1 the remaining time and covered L2=200-L1 for L2/v1 s. There are two unknowns: a and v1 (or t1), and there are two input data: L=L1+L2= 200m and T=19.3s, for example. Two equations for two unknown parameters suffice to find them.

Last edited: Oct 21, 2009
6. Oct 21, 2009

### Molydood

you need the splits from each 10 metre segment.
you can probably find these for 100m race but not sure about 200m. The other option is to analyse a video, but you need clear markers on the track and there may not be any.

7. Oct 21, 2009

### Staff: Mentor

100m is a google search away.

8. Oct 21, 2009

### HallsofIvy

Staff Emeritus
9. Oct 21, 2009

### Staff: Mentor

That's 100 meters, not 200 OP is looking for.