Newton's Second Law says that force is equal to mass times acceleration. If the car and washer were more massive, you would need (more / less) force to accelerate car and washer equally. (5 pts)

You would need more force if the car were bigger. If the car was bigger, then it would be heavier. Think about it like this - you are pulling a wagon. Suddenly, a child comes and sits in the wagon. Because the child is heavier, it's harder to pull the wagon, so you must exert more force in order to pull it.