Which method of testing substances is a sure way to identify a chemical reaction? a. change in color b. formation of bubbles c. change in density d. increase in temperature e. solubility in water

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

The bubba chump shrimp company processes and packages shrimp for sale to wholesale seafood distributors. the shrimp are transported to the main plant by trucks that carry 1,000 pounds (lb) of shrimp. once the continuous flow processing of the shrimp begins, no inventory is allowed in buffers due to spoilage and all of the shrimp must be processed within 12 hours to prevent spoilage. the processing begins at the sorter, where the trucks dump the shrimp onto a conveyor belt that feeds into the sorter, which can sort up to 500 lb per hour. the shrimp then proceed to the desheller, which can process shrimp at the rate of 400 lb per hour. however, after 3 hours and 45 minutes of processing, the desheller must be stopped for 15 minutes to clean out empty shrimp shells that have accumulated. the veins of the shrimp are then removed in the deveining area at a maximum rate of 360 lb per hour. the shrimp proceed to the washing area, where they are processed at 750 lb per hour. finally, the shrimp are packaged and frozen. what is the daily process capacity of the processing plant (excluding the packaging and freezing)?

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?