It is estimated that uranium is relatively common in the earth's crust, occurring in amounts of 4 g / metric ton. a metric ton is 1000 kg. at this concentration, what mass of uranium is present in 1.2 mg of the earth's crust?

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?