My department just switched to the latest version of Serway - Physics for Scientists and Engineers. The following problem is presented in chapter 5 (prob 26):
"A car is moving forward slowly and is speeding up. A student claims "the car exerts a force on itslf" or "the car's engine exerts a force on the car" Argue that this idea cannot be accurate and that friction exerted by the road is the propulsive force on the car."
How would members of this list respond to this problem? If I am standing on ice and push off from a rigid wall, is it the wall providing the propulsive force on my torso or is it the muscles in my arm?