An experiment is designed to test what color of light will activate a photoelectric cell the best. The photocell is set in a circuit that "clicks" in response to current. The faster the current, the more clicks per minute. In this experiment, the number of clicks in one minute is recorded for each color of light shining on the photocell. To change the color of light, a different color of cellophane is placed over the same flashlight and the flashlight is then located a specific distance from the photocell. Which of the following was not kept constant?
In the above experiment, which factor is the independent variable?
Which of the following would be the best hypothesis for this experiment?

the test for photocell activation

the color of the light after it has passed through the cellophane

the distance of the light from the photocell

the source of the original light

1. The color of the light after it has passed through the Cellophane

2. The color of the light

3. If photoelectric cells respond better to short wavelengths of light, the red light should activate it the least and the blue the most.

Explanation:

1. The color of the light changes depending on what color cellophane is put in front of the flashlight

2. The color of the light is the independent variable because it is the only part of the experiment that is being altered.

3. In the description they say the purpose of the experiment is to determine what color of light will have the largest affect on the photoelectric cell. Therefore, this matches up best. The one where is says Photoelectric cells are affected by different wavelengths of light doesn't mention which one is better just that they are affected.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2

this would be about 43%