Research Question: How does changing the height for a tennis ball to drop affect the time? Independent variable: Height (1m, 1.25m, 1.50m, 1.75m, 2.00m) Dependent variable: Time (seconds)
Control variables: Tennis ball, Positions, Place, and Stopwatch
What is important to keep the same?| How will they be controlled?| Why should they be controlled?| Tennis ball| By using the same tennis ball| If the size or weight of the tennis ball is different it will affect the time for it to drop.| Place| Staying in the same place. | Different place has different winds speed or in some places the ball doesn’t bounce much.| Positions| Each person does the same job.| Different people have different strength, mass, weight and etc.|
Hypothesis with explanation: The shorter the distance, the less time it will take for the tennis ball to drop, because if the ball is higher, the more distance it has to cover, thus meaning it will take longer to reach the ground.
1 measuring tape
1 tennis ball
1. Using a measuring tape measure 1 meter
2. Place the tennis ball on the measure of 1 meter
3. Drop the tennis ball and start the stopwatch at the same time 4. Stop the stopwatch when the ball touches the surface of the floor. 5. Record this in a table
6. Do this again 5 times and calculate the average.
7. Increase the height by 25cm
8. After that, Place the tennis ball on the height increased by 25 cm (1.25m) 9. Repeat step 3-6 four more times
10. Next, place the tennis ball on the height increased by 25 cm (1.50m) again. 11. Repeat step 3-6 four more times
12. Place the tennis ball on the height increased by 25cm (1.75m) again. 13. Repeat step 3-6 four more times
14. Lastly place the tennis ball on the height increased by 25cm (2.00m) again 15. Repeat step 3-6 four more times.