If the half-life of an isotope of cobalt is 60 years. How much of a 3- gram sample will be left after 300 years?

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