Runner's Distance from Starting Point after 11.5 Seconds

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mrlevis
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Homework Statement


A velocity of a runner is described in the graph below. The runner started from X=0 on the X axis. In what distance from X=0 (beginning) will be the runner, after 11.5 sec.

Velocity against time graph: velocity in m/s on the vertical axis and time in s on the horizontal axis, 0 to 14 s. Velocity is constant at 2 m/s from 0 to 4 s, rises to 8 m/s by 6 s, stays at 8 m/s until about 8 s, falls to 6 m/s by 10 s, stays at 6 m/s until 12 s, then drops to 0 by about 13 s.

Homework Equations


The Attempt at a Solution



Please tell me why it isn't 42m.:confused:
 
V=m*s, so that means the area of the graph gives us the distance from X=0. then;

32(the 2*1 areas)+ 4 (the first triangle) + 2 (the second triangle) (from X=0 to 10. sec)

now calculate the +1,5 sec area which is 1,5*4=6

then 38+6=44, right?
 
Last edited:
Thanks goktr001, but i have just solved it, its actually 44.
I summed the area under the graph, but only till the 11sec, i didnt notice that 11.5 is actually 3 quarders of triangle.

Problem solved anyway. thanks.