The allegheny and monongahela rivers meet at pittsburgh to form the mighty ohio river. the allegheny, flowing through forests and small towns, runs at an average flow of 340 cubic feet per second (cfs) and has a low solid concentration of 130 mg/l. the monongahela, on the other hand, flows at 460 cubic feet per second (cfs) through old steel towns and farms, carrying a solids concentration of 500 mg/l. conduct a non-reactive mass balance to determine: a. what is the average flow (in cfs) in the ohio river? (10 points) b. what is the solids concentration (in mg/l) in the ohio river? (10 points) your solution must show the system around which mass balance is conducted, the system boundary, the mass balance equations and all assumptions made. show all work clearly.

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below.your friend goes first,and you follow after he has dropped a distance of 2.0m.when your friend hits the water,is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.

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.

10 points! will mark brainiest! in a heat engine if 1,000 j of heat enters the system and the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2,000 j 1: write the equation 2: list out your known variables 3: plug the numbers into the equations 4: solve 5: write your solution statement that includes initial energy and final energy added you so much!