"Light travels at the rate of 300,000 kilometers per second in a vacuum." Which of these statements is correct about this law? A. It is a fact in nature which cannot be tested. B. It is a theory which is not supported by data. C. It is an observation which cannot be explained. D. It is a description which does not work under similar conditions.

The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

If a tank filled with water contains a block and the height of the water above point a within the block is 0.8 meter, what is the pressure at point a?