Ahmad pours 2 tablespoons of vinegar into a cup that contains 250 grams of milk. He watches the mixture change as the milk separates into curds and whey. After the reaction takes place, Ahmad records the mass of the product as 280 grams.

If a car is traveling on the highway at a constant velocity, the force that pushes the car forward must be a. equal to the weight of the car. b. less than the force of friction exerted upon the car. c. equal to the force of friction exerted upon the car. d. greater than the weight of the car.