Physics

In a hydroelectric dam, water falls 26.0 m and then spins a turbine to generate electricity. What is ∆U of 1.0 kg of water? 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 54.0 MW of electricity? This is a typical value for a small hydroelectric dam.

  1. 👍 1
  2. 👎 0
  3. 👁 6,945
  1. potentialenergy= mgh=1kg*9.8N/kg*26m

    massflow*g*h/time * .80=54*10^6
    Flowrate=54^10^6/gh * 1/.80

    1. 👍 2
    2. 👎 1
    👨‍🏫
    bobpursley
  2. If what you are calling ∆U includes the gravitational potential energy*, then it is -(density*g*(delta H)
    = -(10^3 kg/m^3)*26 m*9.81 m/s^2
    The product will be in Joules.

    For P = 54*10^6 Watts, you need a mass flow rate such that
    P = (mass flow rate)*(∆U)

    *Usually, in thermodynamics, U represents internal energy only, which has nothing to do with elevation.

    1. 👍 0
    2. 👎 4
  3. I forgot to include the 80% efficiency factor, but BobPursley did it right

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Science (Please check my answers)

    1) Which statement correctly identifies the relative levels of kinetic and potential energy in a hydroelectric dam?(1 point) Kinetic and potential energy are both highest at the top. Kinetic energy is highest at the top; potential

  2. Algebra2

    Wind farms are a source of renewable energy found around the world. The power P (in kilowatts) generated by a wind turbine varies directly as the cube of the wind speed v (in meters per second). If a turbine generates 500kW in a

  3. Science**updated asnwers**

    5.B 6.A 7.C 8.D 9.A 11.D 13.D 5. Which of the following types of pollution cannot be attributed to car and truck emissions? A. acid rain B. sedimentation C. ozone D. photochemical smog 6. Which of the following is a source of

  4. algebra

    Wind farms are a source of renewable energy found around the world. The power P(in kilowatts) generated by a wind turbine varies directly as the cube of the wind speed v(in meters per second) If a turbine generates 700kW in a 5m.s

  1. Science

    The Hoover Dam is a hydroelectric power plant that converts the energy of falling water into electricity. Which of the following determines the amount of potential energy of the water stored in the reservoir of the dam? Choose all

  2. Physic

    A dam is used to block the passage of a river and to generate electricity. Approximately 58.4 x 103 kg of water falls each second through a height of 20.1 m. If one half of the gravitational potential energy of the water were

  3. AP PHYSICS

    the height of the upper falls at Yellowstone falls is 33.2m. when the water reaches the botton of the falls, its speed is 25.8 m/s. neglecting air resistance, what is the speed of the water at the to of te falls.

  4. physics

    A wind turbine is initially spinning at a constant angular speed. As the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.170 rad/s2. After making 2870 revolutions, its angular speed

  1. physics

    A dam blocks the passage of a river and generates electricity. Approximately 57,000 kg of water fall each second through a height of 19 m. If one half of the gravitational potential energy of the water were converted to electrical

  2. science help pls pls

    Dams are used to produce hydroelectric power. Which of these best describes the impact of a dam on the environment? It causes air pollution. It reduces the level of groundwater. It causes changes in the river ecosystem. It reduces

  3. 3 science questions

    7. Which of the following is used to make biomass fuel? B. plants and animal waste C. coal

  4. physics

    Hi guyys, could you help me with this question. The center of a circular floodgate of radius 0.5 m is located in a dam at a depth of 2 m beneath the free surface of the water contained by the dam. Calculate the force exerted by

You can view more similar questions or ask a new question.