What is one way that kinetic energy can be transformed into another form of energy?

Can someone me with questions 15 to 17 plz.

How many atoms are there in 5.70 mol of mg

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d