As part of a safety investigation, two 1900 {\rm kg} cars traveling at 18 {\rm m/s} are crashed into different barriers.

As part of a safety investigation, two 1900 {rm kg} cars traveling at 18 {rm m/s} are crashed into different barriers. Find the average forces exerted on (a) the car that hits a line of water barrels and takes 1.8 {rm s} to stop, and (b) the car that hits a concrete barrier and takes 0.1 {rm s} to stop.What are F1 and F2? Use two significant figures.