Question

Applying the Scientific Method to an Experimental Study---

Your friend claims that sunlight affects the temperature of water

^^ I need to develop an experiment to test this claim

What is the Null and alternative hypothesis ???

1. Identify the Independent variable for your experiment.

2. Identify the Dependent variable for your experiment.

3. List at least 3 variables that you would hold constant in your experiment.

4. Now design the experiment: Identify and use at least five of the following lab equipment pieces to design your experiment. Provide a brief description of the experiment. Include a description of the Control Treatment and the Experimental Treatment

Answer 1

Ans: Experiment on sunlight affects the temperature of water

Null hypothesis: Sunlight affects the water temperature. There is correlation between sunlight and water temperature.

Alternate hypothesis: Water temperature is not affected by sunlight but by other factors. There is no any correlation between sunlight and water temperature.

Independent variable for the experiment: Independent variable is the condition that you change in an experiment. It is the variable you control. So Independent variable is sunlight in this experiment.

Dependent variable for the experiment: Dependent variable is the condition that you measure in an experiment. So temperature of water is dependent variable in this experiment.

3 Variables that you would hold constant in the experiment: Pressure, humidity, Components of air

Design the experiment:

A cup of water is placed in the sunlight and another cup of water is placed in the shade for 1 hour. The changes in temperature of water are measured to study effect of sunlight on water temperature. Student will record observations by measuring water temperature in both situations and come to conclusion.

Control Treatment: Cup of water is placed in the shade is control treatment

Experimental Treatment: Cup of water is placed in the sunlight is experimental treatment

Materials required: 2 plastic clear cups, water marker 2 thermometers, measuring cup

Procedure:

Take two empty cups and label Sunlight and no sunlight.

Pour the ½ cup of water into both the cups.

Draw a data table in as follows.

Temperature	Cup in Sunlight	No Sunlight
At Beginning
After 1 hour
Difference

Record the readings as per table. Find the difference and conclude.