Which item has the most potential energy (assume they are all at the same height and mass)? a) rock b) magnet c) battery d) light bulb

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

Light that is polarized along the vertical direction is incident on a sheet of polarizing material. only 96% of the intensity of the light passes through the sheet and strikes a second sheet of polarizing material. no light passes through the second sheet. what angle does the transmission axis of the second sheet make with the vertical?

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?