A typical propeller of a turbine used to generate electricity from the wind consists of three blades as in the figure below. Each blade has a length of L = 33 m and a mass of m = 415 kg. The propeller rotates at the rate of 21 rev/min. 120degree angle between blades
a) Convert the angular speed of the propeller to units of rad/s.
(b) Find the moment of inertia of the propeller about the axis of rotation.___J · s2
(c) Find the total kinetic energy of the propeller.______ J

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
  1. This is pretty standard question. What is it you do not understand?

    For the moment of inertial figure each blade rotating about its end, then multiply by three.

    KE=1/2 Itotal*w^2

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
  2. (A) w = (21rev/min) * (1min/60sec) * (2pi rad/1rev) = 2.2 rad/s


    I = MR^2
    I = (415kg)(33m)^2
    I = 4.52E5 (I for one propeller)

    I for all three propellers = (4.52E5) * 3 = 1.36E6

    (C) KE = (1/2) * Iw^2

    = (1/2)(4.52E5)(2.2)^2
    =1.1E6 J

    The book gives solutions for I and KE using one propeller. My thought were to multiply I *3....a little confusing. Thoughts...?

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩

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. Physics

    A propeller spins at 1880 rev/min. the equals 197 rads/sec b. What is the angular displacement of the propeller in 2.50 s ?

  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. IB Physics

    a wind turbine has a power output p when the wind speed is v. The efficiency of the turbine does not change. What is the wind speed at which the power output is p/2 I know the answer is v/cube root of 2 but I don't know how to get

  2. Physics

    A turbine is spinning at 3600rpm . Friction in the bearings is so low that it takes 11min to coast to a stop. How many revolutions does the turbine make while stopping?

  3. science

    Which statement correctly identifies the relative levels of kinetic and potential energy in a hydroelectric dam? A. Kinetic energy is highest at the bottom; potential energy is highest at the top.****** B. Kinetic and potential

  4. algebra

    suppose the polynomial function below represents the power generated by a wind turbine where x represents the wind speed in meters per second and y represents the kilowatts generated interpret f(10) f(x)=0.08x^3+x^2+x+0.26

  1. Physics

    Q) Rows of wind-powered generators are used in various windy locations to generate electric power. Does the power generated affect the speed of the wind?Would Locations behind the windmills be windier if they weren't there? Dicuss

  2. 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

  3. ELA

    Hello! I just wanted to double check my answer to see if I am thinking correctly. Read this passage: The principle of the mercury boiler is the utilization of mercury between the fire and the under-boiler surface exposed to the

  4. Science

    Which of the following is not part of the process of producing electricity from coal? 1. Coal is lifted onto a platform to give it potential energy before burning. 2. Coal must be burned to release heat. 3. Heating water produces

View more similar questions or ask a new question.