Your friend's car is broken and you volunteer to push it to the nearest repair shop which is 2.0 km away. You carefully move your car so that the bumpers of the two cars are in contact and then slowly accelerate to a speed of 2.5 m/s over the course of 1 min.
(a) If the mass of your friend ‘s car is 1200 kg, what is the normal force between the two bumpers?
(b) If you then maintain a speed of 2.5 m/s, how long does it take you to reach the repair shop?