Answer:
Independent variables
Step-by-step explanation:
Variables can come in either a dependent or an independent variable.
The dependent variable is the major test objective in every experiment as it reacts to the changes made to the independent variables.
The independent variable is the primary variable in an experiment that is changed to know its effect on the dependent variable.
The speed and distance covered can be dependent variables that depend on changes made to driving skills , road surfacing , lubricants , tires , brakes and the weight of a car.