Answer:
The responding (dependent) variable
Step-by-step explanation:
In an experiment, one of the variables is either changed/maipulated or measured. The variable that is deliberately changed is called the INDEPENDENT VARIABLE while the variable that responds to the changes made to the independent variable, or is being measured is called DEPENDENT VARIABLE.
Hence, in the experiment involving the height of the ramp and the speed of the skateboard, the SPEED OF THE SKATEBOARD IS THE DEPENDENT/RESPONDING VARIABLE because it is the variable being measured.