Question 150990
suzy can run 4m/sec and tim can run 6m/sec. How far ahead of tim must suzy be to not to fall behind tim in the first 10 seconds of running? Use a graph to check your answer?
:
Let d = distance that T is ahead of S
:
Write a distance equation: Dist = speed * 10 sec
:
S's dist + head-start dist = T's dist
4(10) + d = 6(10)
40 + d = 60
d = 60 - 40
d = 20 m head start
:
"Use a graph to check your answer"
let x = time running
let y = distance ran
;
Suzy:  y = 4x + 20; (green)
:
Tim:   y = 6x; (purple) 
:
y axis = dist, x axis = time
{{{ graph( 300, 200, -5, 15, -10, 100, 6x, 4x+20) }}}
You can see that T (purple) passes S (green) at 10 sec
And when x=0, S has a 20m headstart