A car with two passengers traveling at 15 m/s collides with a tree. One of the passengers who is not wearing a seat belt strikes the windshield head first and comes to rest in 0.03 s. The area of contact between the head and the windshield is approximately 5x10 m² and the mass of the head is 5.4 kg. The other passenger who is wearing his seat belt comes to rest in 0.50 s. The mass of this passenger is 75 kg. The area of the seat belt in contact with this passenger is about 0.12 m². Find the average force and the force per unit area exerted on the two passengers. ​