Part A In a hydroelectric dam, water falls 33 m and then spins a turbine to generate electricity. What is AU of 1.0 kg of water? Express your answer with the appropriate units. ▸ View Available Hint(s) AU = 324 Submit Previous Answers ? J × Incorrect; Try Again; 4 attempts remaining Part B Suppose the dam is 80% efficient at converting the water's potential energy to electrical energy. How many kilograms of water must pass through the turbines each second to generate 49 MW of electricity? This is a typical value for a small hydroelectric dam. Express your answer in kilograms per second. ▸ View Available Hint(s) ΑΣΦ www ? m 1 s 173933.2 kg/s Submit Previous Answers × Incorrect; Try Again; 5 attempts remaining

Water falls over a dam of height h with a mass flow rate of Iv, in units of kilograms per second. (a) Show that the power available from the water is P = Ivgh where g is the free-fall acceleration. (b) Each hydroelectric unit at the Grand Coulee Dam takes in water at a rate of 8.50 105 kg/s from a height of 87.0 m. The power developed by the falling water is converted to electric power with an efficiency of 85.0%. How much electric power does each hydroelectric unit produce?

Consider the energy transfers and transformations listed below in parts (a) through (e). For each part, (i) describe human-made devices designed to produce each of the energy transfers or transformations and, (ii) whenever possible, describe a natural process in which the energy transfer or transformation occurs. Give details to defend your choices, such as identifying the system and identifying other output energy if the device or natural process has limited efficiency. (a) Chemical potential energy transforms into internal energy. (b) Energy transferred by electrical transmission becomes gravitational potential energy. (c) Elastic potential energy transfers out of a system by heat. (d) Energy transferred by mechanical waves does work on a system. (e) Energy carried by electromagnetic waves becomes kinetic energy in a system.

The Huka Falls on the Waikato River is one of New Zealand's most visited natural tourist attractions. On average, the river has a flow rate of about 300,000 L/s. At be gorge, the river narrows to 20-m wide and averages 20-m deep. (a) What be average speed of the river in the gorge? (b) What is the average speed of the water in the river downstream of the falls when it widens to 60 m and its depth increases to an average of 40 m?