A block of mass 15.0 kg is suspended from a heavy metal ring by a vertical wire. The ring is suspended from the ceiling by two wires. The left wire has a tension of 283 N and makes an angle
of a = 31.0° with the ceiling. The right wire makes an angle of b = 68.0° with the ceiling. Find the
mass of the ring.

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

In a system, when potential energy decreases, then entropy also decreases. true false

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.