Passage
Students studied how quickly water evaporates from an open dish. In each trial they filled a shallow dish with water, left it uncovered for 24 hours, and measured the mass of water lost (the water evaporated) by weighing the dish before and after.
Study 1: Using the same dish, which had an open surface area of about 60 cm^2, the students placed it in rooms held at different air temperatures and recorded the water evaporated in 24 hours (Table 1).
| Air temperature (°C) | Water evaporated in 24 h (g) |
|---|
| 20 | 8 |
| 25 | 12 |
| 30 | 17 |
| 35 | 23 |
| 40 | 30 |
Study 2: Holding the air temperature at 30°C, the students used dishes of different open surface areas and again measured the water evaporated in 24 hours (Table 2).
| Open surface area (cm^2) | Water evaporated in 24 h (g) |
|---|
| 20 | 6 |
| 40 | 12 |
| 60 | 18 |
| 80 | 24 |
In every trial the dishes were left uncovered for the same 24-hour period, and the water and the surrounding air were otherwise the same.
