4.2 hours, do 315 miles / 75 miles per hour
According to the law of conservation of mass, the mass of reactants will be equal to the mass of the products. The mass of products and reactants will only differ during a nuckear reaction
Changing of the physical state of water is not a nuclear reaction. So becoz of that the mass will remain constant without any change.
Because all matter has density and since air has density then air is matter and plus EVERYTHING is made of matter