The picture below shows a train as it approaches a hill. This train can only make it over the hill if it approaches at it's top speed because it will
lose speed as it climbs. What changes are taking place in the train's
potential and kinetic energy as it climbs the hill?

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green

Select the correct answer. why are scientific models important in the study of science? a. they always involve critical mathematical calculations. b. they scientists understand complex ideas and objects that aren’t easy to handle. c. they enable scientists to popularize their work in society. d. they are required when conducting any peer review process. e. they are necessary for turning a hypothesis into a law.