Believe it or not gravity is not really a force, it is an acceleration and on Earth it is about 32 feet/sec2. This same science principle applies in decelerating devices like parachutes and parafoils. The parachute decelerates or slows down the fall of the object.
What is a .DS_Store or ._ AppleDouble file? .DS_Store files are created by OS X to store metadata about folders and files including viewing options, icon positions and color labels. ._ AppleDouble files are created by the OS X when an application adds resource data or metadata to a file on a disk whose format doesn't support resources or metadata.
One of those hidden folders will be $Windows.~WS . You can view these folders by un-hiding the hidden folders from the View panel at the top. Having a look at the size of this folder, you will notice that it has occupied a huge space inside your Windows drive. So, a lot of questions arise about the presence of this folder.