WayCoolScience7 - Scenario 4 pd 7

Donna's Pendulum Experiment
Donna has observed that her father can control the speed of their grandfather clock by adjusting the height of the weight on the end of the pendulum. Donna thinks that the pendulum will move faster when the weight is lowered, and wants to test her idea. Donna gets a stopwatch and measures the time it takes for the pendulum to swing twenty times when the weight is moved to its lowest position. Donna begins to move the weight up by 1 cm and continues to measure the time for twenty swings of the pendulum. Donna records her data:
Measurements made from the bottom up. So 1 cm is lowest position and 5 cm is highest position.

Position	Time (seconds)
1 cm	23.23
2 cm	21.56
3 cm	20.33
4 cm	19.00
5 cm	18.02

Complete each of the following:

Identify Donna's hypothesis: Donna's hypothesis is that the pendulum will move faster when the height of the weight is lowered.
Identify the independent variable: The independent variable is the height of the weight of the pendulum.
Identify the dependent variable:The dependent variable is the twenty swings of the pendulum for each position.
Identify the other variables Donna needs to consider/control during this experiment: type of clock(brand), quality of clock, quality of pendulum, environmental conditons, material used to make clock, material used to make pendulum
Identify the control group in this experiment: The control group is the twenty times when the weight is at its lowest point.
Identify the experimental group(s): The groups with the other positions.
What conclusion might Donna draw from this data?The conclusion Donna might draw is that when the height of the weight is lowered it does move faster.
What recommendations might you suggest for further study or for improvement? One recommendation is that the time of the pendulum swings with no weight on it should be included.