Because of friction... A. energy is always not conserved
B. not all potential energy is converted into kinetic energy
C. all of an object's kinetic energy turns into potential energy
D. all of an object's potential energy turns into kinetic energy

Dry ice is solid carbon dioxide that is used in the transport of food and medicine. dry ice becomes a gas at –78.5°c without becoming a liquid first.

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is transformed ⇒ as it changes into other forms of energy.

Unpolarized light whose intensity is 1.19 w/ is incident on a polarizer. (a) what is the intensity of the light leaving the polarizer? (b) if the analyzer is set at an angle of = 41.0∘ with respect to the polarizer, what is the intensity of the light that reaches the photocell?