A roller coasters velocity at the top of the hill is 15 m/s. Two seconds later it reaches the bottom of the hill with a velocity of 30 m/s. What is the acceleration of the coaster?

Please help due today

This is what i found on google “lithium and sulfide can react together to form litium sulfide(li2s). when lithium sulfide hydrolyses(breaks down) in air, it releases hydrogen sulfide which is characteristized by a rotten egg odor.” i hope this you for what your looking for

Answershe should not have multiplied the sulfur atoms by the subscript 4