It is January and Haley, Sarah and Becky are tired of having cold feet while waiting for the school bus to come in the morning. They decided to design an experiment to test the effectiveness of wool, cotton, a nylon as insulators. They fill identical bottles with 200 ml of water at 100 c and place inside each sock. They take the temperature of the water after 20 mins.

Question

Identify the constants that are listed for this experiment. Select all that apply

Amount of water

Cold days in January

Wool, cotton, and nylon materials

Temperature of water

Feet temperature

Answer 1

In the described experiment, the constants are the factors that are kept the same to ensure that any changes in the results can be attributed to the varying types of insulation (wool, cotton, and nylon).

Here are the constants from your list:

1. Amount of water - This is constant as each bottle contains 200 ml of water.
2. Temperature of water - The initial temperature is set at 100°C for all samples.

The other options you provided would not be considered constants for the following reasons:

• Cold days in January - While this provides context for why they are testing insulation, it does not directly influence the experimental setup and is not kept constant across the experiment since it is about the ambient conditions outside.
• Wool, cotton, and nylon materials - These are the variables being tested, not constants, as they represent different types of insulation.
• Feet temperature - This is not part of the experimental setup since the experiment is focused on the temperature of the water inside the bottles.

Thus, the correct constants for this experiment are:

• Amount of water
• Temperature of water