Acar moving at 20m/s slows down to 10 m/s find the change in kinetic energy

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.

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?