A student investigates how the thickness of insulation around a beaker affects how quickly hot water cools down.
She wraps four identical beakers in different numbers of layers of newspaper.
This is the student's plan:
State the independent variable in this investigation.
State one variable (other than the volume of water) that the student plans to control.
Explain why it is important to control this variable.
Suggest a safety precaution for this investigation.
Complete the table by calculating each missing temperature difference:
| Number of layers of newspaper | Starting temperature in ∘C^{\circ}\text{C}∘C | Temperature after 12 minutes in ∘C^{\circ}\text{C}∘C | Temperature difference in ∘C^{\circ}\text{C}∘C |
|---|---|---|---|
| 1 | 84 | 52 | |
| 3 | 88 | 63 | |
| 5 | 81 | 61 | |
| 7 | 84 | 68 |
The student wants to display the data on a graph. Give suitable labels for the axes of her graph.
The student realizes that it was a mistake to have different starting temperatures. Suggest how she could modify her method to correct this mistake.