X
Hot air rises = it's less dense than cold air = falls
D
Its D i think because it doesnt refer to any other things
Fill in the blank --
A radio controlled car rolls 10 m south, then reverses direction and rolls 8 m north.
The car has traveled a distance of 18 m and has a displacement of 2 m south
↑ ↑ ↑ Hope this helps! (The bolded number is the unknown value/blank)