Omar wants to determine if the mass of a model rocket affects how long the rocket is able to stay up in the air. To do this, he constructs three identical rockets and then fills two of the rockets with varying amounts of sand to add mass. He then launches the rockets one at a time and times how long they are able to stay airborne. What is the test variable (independent variable) in Omar's experiment?

To do this, he constructs three identical rockets and then fills two of the rockets with varying amounts of sand to add mass.

Explanation:

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.