what are the pros and cons of using A radio telescope, 300 meters in diameter, located in Puerto Rico for observing matter around a black hole; assume that the matter is emitting photons at all wavelengths.

Assuming weightless pulleys and 100% efficiency, what is the minimum input force required to lift a 120 n weight using a single fixed pulley?

An object has a weight of 500 on earth what is the mass of this object

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.