___ transport, molecules move from areas of concentration to concentration across a cell membrane, which requires no to be used. Diffusion, , and diffusion are examples of passive transport that the uses to move in and out of a cell.

Johnny rode his bike 4 blicks down the street to his friend's house once he got to his friend house and realized he could not cone out to play he turned aroubd and went back home. what is displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point