During which stage of meiosis is the diploid number of chromosomes reduced to haploid

Which scenario is most similar to the type of collision that gas particles have according to kinetic molecular theory

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.

How is the solubility of a carbon dioxide gas in water increase?