"A car is traveling at 70.4 m/h on a horizontal highway. The acceleration of gravity is 9.8 m/s^2. If the coefficient between the road and tires on a rainy day is 0.052, what is the minimum distance in which the car will stop?" I can't figure out how to solve this problem. To find the frictional force, I need the normal force, and to find the normal force I need the mass right?