Alight-year is a unit of
a. time.
c. mass.
b. distance.
d. density.

Unit of distance. B.

Light year is the distance traveled by light in one year.

Not sure but i think it's b.

They coasters are in tear-drop form because of physics. if the ride was in a complete circle, how would the coaster get into the loop, let alone get out of the loop? also, the reason why most coasters are in tear-drop form is because of acceleration. the steeper the turn, the faster the ride.