Final answer:
The energy source that powers Joey's car to open the windows is the hand crank mechanism that converts human-powered energy into mechanical energy.
Step-by-step explanation:
The energy source that powers Joey's car to open the windows comes from the hand crank mechanism. When Joey uses the hand crank, it converts human-powered energy into mechanical energy, which is then used to open the windows. The moving car itself does not directly provide the energy to open the windows.