A power-generating windmill is being designed and will consist of a tower with three large blades that rotate on a central hub at the top of the tower. The height of the tower from the ground to the center of the hub where the 3 blades meet is 262 feet, and the length of the blades from the center of the hub to the tip of each blade is 148 feet. The tower is in the shape of a right circular cylinder that has a diameter of 40 feet, as shown in the figure.QuestionAs the blades rotate they span an area and displace the air in that area. In 13 of a full rotation of one of the blades, which of the following is closest to the area, in square feet, that the blade spans?
Question
A power-generating windmill is being designed and will consist of a tower with three large blades that rotate on a central hub at the top of the tower. The height of the tower from the ground to the center of the hub where the 3 blades meet is 262 feet, and the length of the blades from the center of the hub to the tip of each blade is 148 feet. The tower is in the shape of a right circular cylinder that has a diameter of 40 feet, as shown in the figure.QuestionAs the blades rotate they span an area and displace the air in that area. In 13 of a full rotation of one of the blades, which of the following is closest to the area, in square feet, that the blade spans?
Solution
Para resolver esta pregunta, sigamos los siguientes pasos:
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Calcular el área total que abarcan las aspas en una rotación completa:
- La longitud de cada aspa desde el centro del cubo hasta la punta es de 148 pies.
- El área que abarcan las aspas al rotar es un círculo con radio de 148 pies.
- El área de un círculo se calcula con la fórmula , donde es el radio.
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Calcular el área total:
- Primero, elevamos 148 al cuadrado:
- Luego, multiplicamos por :
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Calcular el área que abarcan las aspas en de una rotación completa:
- Dado que queremos el área para de una rotación completa, dividimos el área total entre 3:
Por lo tanto, el área más cercana que abarcan las aspas en de una rotación completa es aproximadamente 22,950.24 pies cuadrados.
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