Check the box for the best law of motion the statement applies. Only check one law per statement. Law Being Described 1st 2nd 3rd explains a rocket taking off a child is easier to push in a swing than an adult inertia an object in motion stays in motion F=ma for every action there's an equal and opposite reaction an object at rest stays at rest explains why a car going 70 mph is harder to stop than a car going 20 mph