A device used for mixing consists of three identical thin rods extending from a central axle, all in the same plane, and spaced apart from each other by 120°. Each rod is 10.4 cm long, and attached to the end of each rod is a ball with a cross-sectional area 4.50 cm². Each ball has a drag coefficient of 0.520. A motor drives the central axde, causing the device to rotate. (a) How much power (in W) must be supplied by the motor for the device to rotate at a constant speed of 1000 rev/min in air? (Use 1.20 kg/m for the density of air at 20°C.) 0.532 What is the force of air resistance, and what does it depend on? What torque does this force apply? How is power related to torque and angular speed? How is linear speed related to angular speed? Remember

A device used for mixing consists of three identical thin rods extending from a central axle, all in the same plane, and spaced apart from each other by 120°. Each rod is 10.4 cm long, and attached to the end of each rod is a ball with a cross-sectional area 4.50 cm². Each ball has a drag coefficient of 0.520. A motor drives the central axde, causing the device to rotate. (a) How much power (in W) must be supplied by the motor for the device to rotate at a constant speed of 1000 rev/min in air? (Use 1.20 kg/m for the density of air at 20°C.) 0.532 What is the force of air resistance, and what does it depend on? What torque does this force apply? How is power related to torque and angular speed? How is linear speed related to angular speed? Remember

College Physics

11th Edition

ISBN:9781305952300

Author:Raymond A. Serway, Chris Vuille

Publisher:Raymond A. Serway, Chris Vuille

Chapter1: Units, Trigonometry. And Vectors

Section: Chapter Questions

Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...

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At a construction site, there is a pile of sand in the shape of a cone. The cone has a height of 5 m and a base radius of 8 m. Suppose that the density of the sand is 1400 kg/m3. In order to assemble this pile, energy must be expended to lift each bit of sand (working against gravity) to its final height in the pile. It is known that the energy, E required to lift a mass m (in kg) to a height h (in m) is given by E = mgh (where g can be taken to be 10 m/s2). How much energy is required in total to assemble the pile?
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A 170-lb man carries a 20-lb can of paint up a helical staircase that encircles a silo with radius 30 ft. If the silo is 120 ft high and the man makes exactly four complete revolutions, how much work is done by the man against gravity in climbing to the top? Answer in ft-lbs.
Question 3: A polyamide A-3 flat belt 6 in wide is used to transmit 15 hp under light shock conditions where Ks = 1.25, and a factor of safety equal to or greater than 1.1 is appropriate. The pulley rotational axes are parallel and in the horizontal plane. The shafts are 8 ft apart. The 6-in driving pulley rotates at 1750 rev/min in such a way that the loose side is on top. The driven pulley is 18 in in diameter. The coefficient of friction is 0.8. Analyze the centrifugal tension Fc and the torque T.? 1750 rpm Belt 6 in x 0.130 in 15 hp 6 in 18 in Ibf y= 0.042 in d = 6 in, D= 18 in 96 in
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Countries with excellent wind energy sources decide on national projects for the development of wind energy. Ten percent of the land area will be devoted to 1.5 kW wind energy per person, roughly the amount of electricity used by one person in an industrialized country. 2 MW wind turbine with a rotor of 80 m diameter is placed in the average layout space of the figure. Depending on the wind conditions, the average output is 650 kW per turbine. Calculate the maximum density of a single sphere consistent with this business plan. Align geographic information with Germany, Spain, India and Denmark (they all have active wind power programs), and discuss the possibilities for achieving this goal in each of these countries.