Shawn will conduct a study by rolling a toy car down a ramp. He plans to set the

height of the ramp at 30 centimeters (cm) and record how long it takes the toy car to

reach the end of the ramp. After repeating this process multiple times, he will add a

block with a mass of 10 grams (g) to the toy car and record how long it takes the toy

car to reach the end of the ramp. After conducting several trials, he will add another

block with a mass of 10g to the toy car and record how long it takes the toy car to

reach the end of the ramp. After conducting multiple trials, he will analyze his data

and draw a conclusion. Which statement correctly identifies the test variable

(independent variable) and the outcome variable (dependent variable) of the study?

Independent variable: Car weight (car + block with a mass of 10 grams) Dependent variable: Speed (the time the car takes to descend the ramp)

Explanation:

As you can see in the question above, Shawn wants to check the speed that a car takes when going down a ramp, related to the weight of this case, that is, he wants to know the influence of the weight that the car presents, in its speed in going down a ramp.

In this type of experiment, we can consider the weight that the car presents as the independent variable. This is because independent variables are those that influence a result within the experiment. They happen without the influence of another variable and are factors that impose changes in the analyzed system.

The dependent variable, however, is the car's speed down the ramp. This is because the dependent variables are those that need and are influenced by the independent variable, to achieve a result that can be measured and analyzed.