So you're bored driving down the road (or trying to keep the kids/siblings/friends/spouse occupied for a few minutes - maybe the batteries went on the DVD). There's always the "Is the speedometer really accurate?" question/task that will take up ... well, not much time at all but if you're struggling, it's worth it (trust me, my brother used this on me all the time).
The easy part is figuring out how many seconds per mile, but how in the world do you convert that to miles per hour?? (If you really want to know, the math behind this is in a footnote.)
| Seconds | MPH |
|---|---|
| 45 | 80.0 |
| 46 | 78.3 |
| 47 | 76.6 |
| 48 | 75.0 |
| 49 | 73.5 |
| 50 | 72.0 |
| 51 | 70.6 |
| 52 | 69.2 |
| 53 | 67.9 |
| 54 | 66.7 |
| 55 | 65.5 |
| 56 | 64.3 |
| 57 | 63.2 |
| 58 | 62.1 |
| 59 | 61.0 |
| 60 | 60.0 |
| 61 | 59.0 |
| 62 | 58.1 |
| 63 | 57.1 |
| 64 | 56.3 |
| 65 | 55.4 |
| 66 | 54.5 |
| 67 | 53.7 |
| 68 | 52.9 |
| 69 | 52.2 |
| 70 | 51.4 |
| 71 | 50.7 |
| 72 | 50.0 |
| 73 | 49.3 |
| 74 | 48.6 |
| 75 | 48.0 |
The concept is this. An hour is 3600 seconds (60 minutes times 60 seconds for each minute). We want to see how many miles in an hour. So if it takes 50 seconds to go one mile, we divide 3600 by 50 to see how many miles we would go in an hour; the mph. In that example it would be 72 miles. So to get the mph all we do is divide 3600 by the number of seconds it takes to go a mile.