physics
posted by sam on .
we had to watch an animation which showed two balls, each traveling on a straight horizontal line at different speeds.
the graph of position vs time and velocity vs time are given.
The red ball has a linear graph and the coordinates are (0,0), (1,5), (2,10), (3,15), and (4,20)
for the blue ball:(0,0), (1,1), (2,2.5), (3,4.5), (4,7)
it is asked:
If the motion was allowed to continue the blue (lower) ball would reach the finish line (20m) at some time Δt after the red ball. What is Δt?
i though that it would take the blue ball around 9 seconds to reach the finish line,but I don't think this is right
thanks!

here is the graph given can be seen if you search
"constant velocity versus constant acceleration" on google its the first link 
Sam, The response to
"physics  sam, Thursday, May 28, 2009 at 11:43pm"
had been posted last night, even with a suggested correction that you have made this morning.
Would you like to check back before we continue? 
physics  PC, Friday, May 29, 2009 at 12:18am
Here is a copy of the previous response.
> (0,0), (1,1), (2,2.5), (3,5), (4,7)
Could you check the data for the blue ball to see if it is not:
(0,0), (1,1), (2,2.5), **(3,4.5)**, (4,7)
If that's the case, you will find that the function of the blue ball is
y=f(x)=(x^2+3x)/4
in which case you can easily solve for
f(x)=20 
I did that, and the answer came out to be 10.57, which isn't right.
I wasn't sure if a picture of it would help at all? 
I have uploaded a graph but I am unable to show the link as I do not have privileges to do so. Sorry.

The answer is the solution to the equation
(x^2+3x)/4=20
Do you have difficulties finding the solution to the above equations? 
Hello Sam, here'is the link to the graph you requested:
http://i263.photobucket.com/albums/ii157/mathmate/parabola.png