A Fast Start: Watch It!
When you travel, your trip can take longer (or shorter) than you expected. For example, you might get stuck in traffic, stop for a snack, or find a shortcut. Click to watch the beginning of Harry’s trip below.
| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
A Fast Start
In distance–time graphs, people often talk about the steepness of a line. A line gets steeper as it becomes more vertical. The steeper the line, the more quickly a person (or car, or bike) is traveling. Look at the graph of the first part of Harry's trip, then continue reading below.
Harry travels 8 miles in his first hour of riding. He shows his progress by placing a point that lines up with 8 miles on the distance axis and 1 hour on the time axis on his graph, and then he draws a red line from the origin to the point. The red line (his actual travel) is steeper than the blue line (his predicted travel), which means he went farther than expected in the first hour.
Notice that the point he adds to the graph is above the point he used to mark where he predicted he would be. This causes Harry to say, "I'm ahead of schedule!"
If Harry continues at this pace, do you think he will arrive at his grandmother’s house earlier, later, or at the expected time? Explain your answer in one to two sentences.
