useless trivia: What Word Means: A Large Knife - A Machete?

Questions

The study of man & culture is known as ________?

motion, forces, light, sound, etc. Is called ______?

The study of populations of animals & plants, a population being a group of interbreeding organisms in a specific region; for example, the members of a fish species in a lake?

The study of sound is ________?

The study of the composition of substances & the changes that they undergo is __________?