***urgent*** 40 points
how can earth’s layers be defined? select the two correct answers.
by their chemical compositions
by their asthenospheres
by their physical properties
by their proximities to the core
by their amounts of land area

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his 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