Which form of energy is used as a roller coaster moves down the track? a roller coaster moving down a track

Chemical energy
Light energy
Mechanical energy
Solar energy

What material does not melt at any temperature

Which formula can be used to calculate the molar mass of hydrogen peroxide

Precision can be defined as the o exact center of a data set. o reproducibility of a measured value. o correlation between two variables that are measured in a data set agreement between a measured value and an accepted value.