1. The problem statement, all variables and given/known data a car of mass 1500kg and decelerating 15ms-2. what is the total force of car on road from all tires? 2. Relevant equations W=mg F=ma 3. The attempt at a solution I'm not sure if the force is simply mg or if it is ma in this case. There is also a frictional force but I don't know if it applies here. mg=15000? ma=22500?