What effect does acceleration have on an object, such as your body, that is made up of many loosely connected parts?

"Air time" has a bizarre effect on your body since your body is not wholly solid - - it is made up of many loosely connected parts. When your body is accelerated, individual part of your body is accelerated independently. The seat thrusts on your back, the muscles in your back thrust on some organs and those organs thrust on other organs. This is why you sense the ride with your whole body. All the parts inside is being pressed around.