Comparing the distances travelled by toy cars from a ramp
This chart shows distances travelled by four toy cars from a ramp raised to different heights. Use the chart and appropriate graphs to find answers to these questions.
- Which car appears to have wheels with the greatest frictional force?
- Which car appears to have wheels with the least frictional force?
- Estimate what distance you think was travelled by the red car when the ramp was raised to 20 cm high.
- Estimate what distance you think was travelled by the blue car when the ramp was raised to 20 cm high.
- How do the distances travelled by the cars at 12 cm and 28 cm compare?
Download the file - ramp.xls 
To answer questions 1 and 2, you will need to find the average distances travelled by the four cars. To do this:
| 1 | Click in cell B9 and type an equals sign in the Formula Bar. This tells Excel that you are going to enter a formula into the cell. | ||
| 2 | Type AVERAGE in the Formula Bar followed by an open bracket (. | ||
| 3 | Now click in cell B2 and, holding down the mouse button, drag the dotted selection box down to cell B8. Type a close bracket ) in the Formula Bar. Press RETURN. | ||
| 4 | The average distance travelled by the blue car will appear in cell B9. | ||
| 5 | To find the averages for the other cars, click in cell B9 and, holding down the mouse button, drag the fill handle across cells C9 to E9. Release the mouse button and the formula will have been copied appropriately to the cells. |  |
|
| 6 | Label Row 9 by typing "Average" in cell A9. | ||
| The cars travelling the longest and shortest average distances can be assumed to have wheels with the greatest and smallest frictional forces. | |||
| 1 | Click in cell A1 and, holding down the mouse button, drag the selection box to cell E8. This will highlight all the cells containing data - but not the Averages row. | ||
| 2 | Click on the Chart Wizard icon in the toolbar. |  |
|
| 3 | When the Chart Wizard dialog box appears, select the Line graph and the "Line with markers displayed at each data value". | ||
| 4 | Click on the Next > buttons - you could give the graph a title and label the axes at Step 3 of 4 - and press Finish to display the graph. | ||
| 5 | The graph will be displayed showing a gap between the markers for 12 cm and 28 cm. | ||
| 6 | To interpolate the data between these points, click on the line tool in the Drawing toolbar at the foot of the screen and draw a line on the graph between the markers for the red car at 12 cm and at 28 cm. If the Drawing toolbar is not present on-screen, select it using Customize... in the Tools menu. | ||
| 7 | Now draw in a line from the 12 cm marker for the blue car and the 28 cm marker. | ||
| 8 | Using the lines you have drawn, you should be able to estimate the distances travelled by the two cars when the ramp was raised to 20 cm (see below). | ||
To answer question 5, you need to draw a graph which shows only these rows of data. To do this:
| 1 | Click in cell A1 and, holding down the mouse button, drag the selection box to cell E1 - this will select the headings. | ||
| 2 | Now hold down the CONTROL (Ctrl) key. Click in cell A4 and, holding down the mouse button, drag the selection box to cell E4 - this will select the 12 cm row. | ||
| 3 | Continue holding down the CONTROL (CTrl) key. Click in cell A7 and, holding down the mouse button, drag the selection box to cell E7 - this will select the 28 cm row. | ||
| 4 | Click on the Chart Wizard icon in the toolbar | ||
| 5 | When the Chart Wizard dialog box appears, select the Column graph and the default setting. | ||
| 6 | Click on the Next > buttons - you could give the graph a title and label the axes at Step 3 of 4 - and press Finish to display the graph. | ||
| 7 | The graph will be displayed showing columns for the cars only at 12 cm and 28 cm high. | ||
| This graph will enable you to make direct comparisons between the distances travelled by the cars at these two heights. | |||
