How to approach Dynamic graph related problems?

Acceleration vs Time graph.?

• I'm practicing for my exam and so I'm studying off practice tests that my professor gave me. One of the problems is an acceleration vs time graph. The question is question #2 on the link below. http://facultyfiles.deanza.edu/gems/lunaeduardo/Physics50Exam1W11.pdf I understand to calculate the velocity, you multiple the acceleration to its given time (at). However, I don't seem to given an acceleration for this. Any advice on how to approach this problem? I feel like the given of "at t=0sm the velocity was +10 m/s" is supposed to help me on solving this problem.

• Answer:

  It's easy. V = V0 + at, you would be right if it were constant acceleration. In case on the pic we have non constant acceleration. So, we can calculate velocity as V = V(0) + square under the acceleration graph V(40) = 10 + 0.5 * (40 + 15) * 7 = 202.5 m/s V(80) = V(40) + 0.5 * 40 * 7 = 202.5 + 140 = 342.5 m/s Good luck!