1. Controlled Experiments

2. Experiment 1:
Dwayne wanted to determine which surface a toy car could move the fastest on. He had a toy car and a ramp that he was going to cover with different materials. He had carpet, tiles, and vinyl to test on the ramp.

3. Experiment 1:
Dwayne wanted to determine which surface a toy car could move the fastest on. He had a toy car and a ramp that he was going to cover with different materials. He had carpet, tiles, and vinyl to test on the ramp. Question: Which surface would a toy car move the fastest on? How does type of surface affect the speed of a toy car?

4. Experiment 1:
Dwayne wanted to determine which surface a toy car could move the fastest on. He had a toy car and a ramp that he was going to cover with different materials. He had carpet, tiles, and vinyl to test on the ramp. Sample Hypothesis: The car would move the fastest on the vinyl.

5. Experiment 1:
Dwayne wanted to determine which surface a toy car could move the fastest on. He had a toy car and a ramp that he was going to cover with different materials. He had carpet, tiles, and vinyl to test on the ramp. Independent Variable (what is changed) The type of surface

6. Experiment 1:
Dwayne wanted to determine which surface a toy car could move the fastest on. He had a toy car and a ramp that he was going to cover with different materials. He had carpet, tiles, and vinyl to test on the ramp. Dependent Variable: (what is measured/data) The speed of the cars

7. Experiment 1:
Dwayne wanted to determine which surface a toy car could move the fastest on. He had a toy car and a ramp that he was going to cover with different materials. He had carpet, tiles, and vinyl to test on the ramp. Constants: (factors kept the same) The cars, how the cars are released, same ramp, same ramp angle

8. Experiment 2:
A student was interested in testing the effectiveness of sunscreen. She was not permitted to experiment on people so she used a sun sensitive paper that changed color when exposed to sunlight. She bought 3 brands of sunscreen with the same SPF factor to test. She also purchased sun sensitive paper to use-she needed 4 sheets. She took 3 sheets of the paper and applied sunscreen to them. The fourth sheet she did not apply any sunscreen.

9. Experiment 2 What is a possible Question for this experiment?
What is a possible Hypothesis for this experiment?
What would be the Independent Variable?
What would be the Dependent Variable?
What Constants are needed?
Is a Control Group needed?
Any problems or issues with this experiment?

10. Experiment 2:
A student was interested in testing the effectiveness of sunscreen. She was not permitted to experiment on people so she used a sun sensitive paper that changed color when exposed to sunlight. She bought 3 brands of sunscreen with the same SPF factor to test. She also purchased sun sensitive paper to use-she needed 4 sheets. She took 3 sheets of the paper and applied sunscreen to them. The fourth sheet she did not apply any sunscreen. Question: Which brand of sunscreen is most effective at protecting skin?

11. Experiment 2:
A student was interested in testing the effectiveness of sunscreen. She was not permitted to experiment on people so she used a sun sensitive paper that changed color when exposed to sunlight. She bought 3 brands of sunscreen with the same SPF factor to test. She also purchased sun sensitive paper to use-she needed 4 sheets. She took 3 sheets of the paper and applied sunscreen to them. The fourth sheet she did not apply any sunscreen Hypothesis: The most expensive sunscreen will work the best at protecting skin.

12. Experiment 2:
A student was interested in testing the effectiveness of sunscreen. She was not permitted to experiment on people so she used a sun sensitive paper that changed color when exposed to sunlight. She bought 3 brands of sunscreen with the same SPF factor to test. She also purchased sun sensitive paper to use-she needed 4 sheets. She took 3 sheets of the paper and applied sunscreen to them. The fourth sheet she did not apply any sunscreen Independent Variable: The brand of sunscreen

13. Experiment 2:
A student was interested in testing the effectiveness of sunscreen. She was not permitted to experiment on people so she used a sun sensitive paper that changed color when exposed to sunlight. She bought 3 brands of sunscreen with the same SPF factor to test. She also purchased sun sensitive paper to use-she needed 4 sheets. She took 3 sheets of the paper and applied sunscreen to them. The fourth sheet she did not apply any sunscreen. Dependent Variable: Observations of the sun sensitive paper

14. Experiment 2:
A student was interested in testing the effectiveness of sunscreen. She was not permitted to experiment on people so she used a sun sensitive paper that changed color when exposed to sunlight. She bought 3 brands of sunscreen with the same SPF factor to test. She also purchased sun sensitive paper to use-she needed 4 sheets. She took 3 sheets of the paper and applied sunscreen to them. The fourth sheet she did not apply any sunscreen. Constants: Same type of paper, same size of paper, same amount of sunscreen, sunscreen spread the same, paper exposed to sun the same amount of time, same SPF for all brands Control: the sheet with no sunscreen

15. Experiment 3
SpongeBob loves to garden and wants to grow lots of pink flowers for his pal Sandy. He bought a special Flower Power fertilizer to see if will help plants produce more flowers. He plants two plants of the same size in separate containers with the same amount of potting soil. He places one plant in a sunny window and waters it every day with fertilized water. He places the other plant on a shelf in a closet and Waters it with plain water every other day. Identify: independent variable, dependent variable, constants. Should this experiment produce valid results?

16. Experiment 4
Raj wanted to find out if the temperature of water affected the dissolving rate of sugar in water. For each experiment, he added 10 grams of sugar to the water of different temperatures (10°C, 15°C, 20°C) and then timed how long it took for the sugar to dissolve completely.

17. Design an experiment
With your group, design an experiment to test signal strength of a cell phone through different materials. (you may use pictures also) Include: question, hypothesis, IV, DV, constants, basic procedure, issues/problems