Please help immediately A uniform stick AB can be balanced on a knife edge 10cm from one end when a weight of 200N is hung from that end .When the knife edge is removed 5cm further from that end, the 200N weight has to be moved to a point 8.75cm from the knife edge to obtain a balance. Find the length of the stick and its weight.

please draw the diagram before solving

What is the most useful equation for electric power?

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is