Hi i need to know the independent variable, the dependent variable and constants for 9 problems here's the first one a study was done to find if different tire treads affect the breaking distance of a car.

The independent variable is tire treads. An independent variable is the part of an experiment that is changed by the scientist.

The dependent variable is braking distance. A dependent variable is the part of an experiment that is measured by the scientist. 

The constant is the type of car. A constant is a quantity that is unknown but assumed to have a fixed value in a specified mathematical context. It cannot be changed or is purposely unchanged during the experiment.

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