If a position time graph has a constant slope, what can you infer about the
acceleration?

Acceleration is zero.

Explanation:

The slope of a position time graph gives the velocity of the body.

If the slope is constant means the velocity is constant.

Now, acceleration is the measure of the change in velocity of a body over a given time interval.

So, the acceleration of a body is directly proportional to the change in velocity of the body.

If there is no change in velocity, this means that the acceleration of the body is zero.

Here, the slope is a constant implying that the velocity is a constant. So, there is no change in velocity. This implies that the acceleration is zero for the body in the given time interval.

Thus, if a position time graph has a constant slope, one can infer that the  acceleration is zero.