determine the number of fins required.

An electric hot water heater consumes 3.1 kilowatts of electricity and converts it to heat. How long will it take the water heater to heat a 67 gallon tank of water from 10 degrees Celsius to 50 degrees Celsius? (1 kilogram of water is 0.37 gallons, 1 Calorie = 4200 J).  It may be helpful to refer back to the weekly handout for guidance on this problem. Your final answer should be in minutes (rounded to the nearest 10 minutes).

Simple Machines-Levers, Inclined Planes, and Pulleys Directions: Use the appropriate equation to answer the following questions. All answers should be recorded below or in your Engineering Design journal. Remember to show all work. A lever has an effort arm that is 5 meters long and a resistance (load) arm that is 3.5 meters long. How much effort is needed to lift a 100 Newton weight? 5K i). Draw the figure representing the problem ii). How much effort is needed to lift a 100 Newton weight? iii). What is the Actual Mechanical Advantage 1. 5m i) AOON 5-5m

There may or may not be one or more mistakes in the solution. Go through the solution carefully and then do the following. 1. State if the solution is correct or incorrect 2. If the solution is incorrect, identify what is the mistake in the solution. Be specific and succinct. 3. If the solution is incorrect, provide the final solution with appropriate steps. Problem: A refrigeration cycle uses refrigerant R-134a to cool down water from 40°C to 20°C. The refrigerant R-134a enters the cycle as saturated liquid at -15°C and exits as saturated vapor at the same temperature. The mass flow rate of R-134a is 0.12 kg/s. The overall heat transfer coefficient is 1400 W/m².K. The surface area of the heat exchanger is 1.4 m². What is the rate at which heat is being exchanged between R-134a and water? Assume that the heat exchanger is perfectly insulated from outside (i.e., there is no convection or radiation with the outside/surrounding). Solution: We know, from the definition of overall heat…