A velocity vs time graph what is the acceleration of the object

The graph is missing, but ill try to answer this anyway.

The acceleration is the rate of change of the velocity; this means that if you know the velocity as a function of time; v (t), you can obtain the acceleration a (t) by differentiate v (t) with respect to time; this is:

a (t) = dv (t) / dt

Them if you have a graph of velocity versus time, you can find the equation of v (t) and then find the acceleration.

For example, if your graph of velocity vs time is a linear relation, then the acceleration will be the slope of the linear relation.

If the object is moving with an acceleration of + 4 m/s/s (i. e., changing its velocity by 4 m/s per second), then the slope of the line will be + 4 m/s/s.