Identify the test (independent) variable, the outcome (dependent) variable, at least 3
controlled variables, and the error Joe made in the following experiment:
Joe Student rolled a toy car down a ramp and measured how far it traveled along the floor.
He recorded the distance along with the original mass of the toy car. Then, he taped a
penny to the roof of the same toy car, measured its new mass, and rolled it down the same
ramp from the same starting position. Again, he measured the distance the toy car traveled
and recorded the data. He taped a 2
nd
penny to the toy car’s roof, measured its new mass,
and rolled it down the same ramp from the same starting position. And again, he measured
the distance the toy car traveled and recorded the data. Based on this data, he concluded
that the greater mass caused the car to roll a greater distance.
The independent variable is the one that you are able to change - the mass of the car.
The dependent variable is distance, because we are seeing what happens to it as a result of changing the car's mass.
Controls:
1. Starting position
2. Path
3. Some options here; e.g., wheels on car, material ramp is made of, atmosphere (still air), etc.
The experimenter should have done several trials of each mass.
The independent variable in this experiment is the mass of the toy car, specifically the number of pennies taped to the roof. The outcome or dependent variable is the distance the toy car traveled along the floor.
Three controlled variables in this experiment could be the ramp angle, the starting position of the car on the ramp, and the surface of the floor.
The error Joe made in this experiment is assuming that increasing the mass caused the car to roll a greater distance. There are multiple other factors that could have influenced the distance traveled, such as variations in the angle of the ramp, the starting point on the ramp, and the surface of the floor. Additionally, other factors like air resistance or the type of wheels on the toy car might also affect the results. To accurately determine the relationship between mass and distance, Joe should have conducted further experiments while keeping these factors constant.
Test (independent) variable: Mass of the toy car (original mass, first penny added, and second penny added)
Outcome (dependent) variable: Distance the toy car traveled
Controlled variables:
1. Ramp: The same ramp was used throughout the experiment, ensuring that the angle and surface condition of the ramp remained constant.
2. Starting position: The toy car was rolled from the same starting position each time to ensure consistency.
3. Measurement technique: Joe used the same method to measure the distance traveled by the toy car for each trial.
Error Joe made in the experiment: Joe concluded that the greater mass caused the car to roll a greater distance. However, the experiment did not control for other variables that might have influenced the distance traveled, such as the presence of friction or the shape of the car. Additionally, only one trial was conducted for each mass, which could lead to variability in the data. To make more valid conclusions, Joe could have conducted multiple trials for each mass and taken averages to minimize the effects of variability.