Hillary is dropping objects that are the same volume. She wants to investigate how an object’s mass affects the average speed at which it travels when dropped until it hits the ground. Which variable must Hillary change during the experiment?

Independent variable: MASS OF OBJECT

Explanation:

In an experiment, the INDEPENDENT VARIABLE is the variable that is subject to change or manipulation by the experimenter. Hence, this question is asking for the independent variable when it says which variable must Hillary change during the experiment.

According to the question, Hillary is trying to investigate how an object’s mass affects the average speed at which it travels when dropped until it hits the ground. This means that the variable she must change/independent variable is the MASS OF OBJECT dropped.

i believe the answer would be b. hope it : )