Final answer:
The position versus time graph of an object that is speeding up is not a straight line, but rather a curve that indicates acceleration, typically a parabola for uniform acceleration.
Step-by-step explanation:
The statement that the position versus time graph of an object that is speeding up is a straight line is false. When an object is speeding up, its velocity is changing, which indicates acceleration. If the acceleration is constant, the position versus time graph will be a curve that gets steeper over time. This curve is typically a parabola for uniformly accelerated motion, not a straight line. A straight line on a position versus time graph would indicate that the object is moving at a constant velocity, not accelerating.