Hillary is dropping objects that are the same volume. She wants to investigate how an object’s mass affects the average speed at which it travels when dropped, until it hits the ground. Which variable must Hillary change during the experiment? A. the timer
B. the drop height
C. the mass of the object
D. the place where she drops it

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

What is the momentum of a 2 kg object moving at 15 meters per second

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.