How to go from acceleration vs time graph to velocity vs time graph?

[physicslover11]

Homework Statement

The figure below shows the acceleration-versus-time graph for a motorcyclist riding along the x-axis. Assume that at t = 0, x = -1 m and v = 2 m/s.

Unless otherwise specified, use the graphical analysis to solve all the questions below. Do not use the kinematic equations or the functional evaluation of the integral, although, if you happen to know these methods, you may use them to check your graphical result.
1) Plot the velocity-versus-time graph for the first 40 s.
2) a) What is the position of the motorcyclist at t = 40 s? b) What is the distance traveled by the motorcyclist in the first 40 s?
3) a) What is the position of the motorcyclist at t = 15 s? b) Using the kinematic equations, find the position of the motorcyclist at t = 15 s. Compare your answer to that obtained in part a).
4) Roughly sketch the position-versus-time graph for the first 40 s.

Homework Equations

i know that Δv=aΔt, Δx=vΔt

The Attempt at a Solution

i don't know where i should start ! please help

 

[johnqwertyful]

You just find the slope of the velocity graph. Remember, acceleration is the SLOPE of velocity. So from t=0 to t=5, the acceleration is 2. So that means that the velocity graph looks like...?

 

[physicslover11]

but how do i get the slope of the velocity graph if the velocity graph is what I am looking for?

 

[Dick]

but how do i get the slope of the velocity graph if the velocity graph is what I am looking for?

The value of the acceleration graph is the slope of the velocity graph. That's whatjohnqwertyful was saying.