Question

the passage below describes an experiment. read the passage and think about the variables that are described. dave noticed that some of the footballs his team used during practice were not fully inflated. he wondered whether fully inflated footballs would travel farther than footballs with a lower air pressure. to find out, dave collected 20 standard footballs. he fully inflated ten of them to an air pressure of 13 pounds per square inch. he inflated the remaining ten to an air pressure of 10 pounds per square inch. dave used a football launcher to launch a ball across a football field. he measured the distance the football traveled and then launched the next ball. dave repeated this with all 20 balls. which of the following was an independent variable in this experiment? hint: an independent variable is a variable whose effect you are investigating. a dependent variable is a variable that you measure. the air pressure in the footballs the distance the footballs traveled

Explanation:

An independent variable is what is changed or controlled in an experiment to test its effect on the dependent variable. Here, Dave changes the air - pressure in the footballs to see its effect on the distance the footballs travel. So, the air - pressure is the independent variable.

Answer:

the air pressure in the footballs