ENGR 230 Dynamics Sections 14'4

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ENGR 230 Dynamics Sections 14.4
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Power

• Power is the flow of energy per unit time
• Units
• Light Bulb 100W
• 1 W 1 Nm/s
• Car Engine 250 Hp
• 1 Hp 0.707 Btu/sec 550 ft lb / sec

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Power

• How much power can a 20 amp circuit at 120 volts
  supply in your home at 66 of full load? How
  many horsepower is that equivalent to?

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More on Power
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Efficiency

• Efficiency Power Output / Power Input

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• Determine the amount of additional power
  required to accelerate a 1300-kg car from 30 to
  60 km/h on an uphill road with a 50 m rise per
  1000 m run in 20 sec. Assume a linear
  acceleration.

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• A river flowing steadily at a rate of 240 m3/s
  is considered for hydroelectric power generation.
  It is determined that a dam can be built to
  collect water and release it from an elevation
  difference of 50 m to generate power. Determine
  how much power can be generated from this river
  water after the dam is built.