If a car hits a wall at 50mph. What force impact does it have on the driver? Is there some very easy to imagine comparsion?

For example, if I am converting CAD/USD (Canadian dollars to U.S dollars) and the exchange rates is 1.2, does that mean 1.2 CAD equals 1 USD or 1 CAD equals 1.2 1.2 USD?...

A. the change in prices of all goods and services over time B. the change in prices of specific goods and services over time C. the change in prices of final goods and services ...