Scientific calculations - using photosynthesis graphs
The table shows a set of results obtained by students investigating the effect of light intensity on photosynthesis. They varied the distance of the plant from the light source. The rate of photosynthesis is the number of bubbles produced per minute.
| Distance from light source in cm | Bubbles produced per minute |
| 10 | 120 |
| 15 | 54 |
| 20 | 30 |
| 25 | 17 |
| 30 | 13 |
| Distance from light source in cm | 10 |
|---|---|
| Bubbles produced per minute | 120 |
| Distance from light source in cm | 15 |
|---|---|
| Bubbles produced per minute | 54 |
| Distance from light source in cm | 20 |
|---|---|
| Bubbles produced per minute | 30 |
| Distance from light source in cm | 25 |
|---|---|
| Bubbles produced per minute | 17 |
| Distance from light source in cm | 30 |
|---|---|
| Bubbles produced per minute | 13 |
If we draw a graph of this data:
Note that the graph is a curve.
Question
From the graph, suggest the rate of oxygen production at a distance of 18 cm from the light source.
40 bubbles per minute.
Using the graph: