Feet and inches or millimeters or centimeters or meters or miles or kilometers
All of the above as it states that "<span>a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers"</span>
If I were to go from the United States to China in one second, that's a large distance in an incredibly short time. I'd say that's pretty fast.
If I were to go from my room to the door of my room in a year, then that would be unbearably slow.
