So his slope is going to be a little bit lower than the average slope. He's going to go a little bit slower. Then he's going to start accelerating. And so his speed, and you'll see the slope here, is getting steeper and steeper and steeper. And then maybe near the end, he starts tiring off a little bit. And so his distance plotted against time might be a curve that looks something like this. And what we calculated here is just the average slope across this change in time.