## How to get velocity and position from an acceleration-time graph?

Consider the plot below describing the acceleration of a particle along a straight line with an initial position of 10 m and an initial velocity of 9 m/s.

1. What is the velocity at 7 s?
2. What is the position at 7 s?
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 Please help me! I got the answer -12 for #1 and -0.5 for #2, but the computer's telling me these are wrong (it's an online worksheet). I don't understand why?
 Well you can use the two default equations. $$v=v_o +at$$ $$x=v_ot+\frac{1}{2}at^2$$ You'll have to use each equation twice for each problem though.