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Quiz practice

  1. Jan 9, 2008 #1
    Got a quiz tmmrw and i want to know what the answers to these review questions are. :D

    1.-The total consumption of electrical energy in the US is about 1.5 x 10to the11th Joules per year.
    a. what is the average rate of electrical energy consumption in watts?
    b. If the population of the US is 300 million, what is the average rate of energy consumption per person?
    c. the sun transfers energy to the earth by radiation at a rate of approx. 1.0 kW per square meter of surface. If this energy could be collected and converted to electrical energy, how great an area (in square meters) would be required to collect the electrical energy used by the US?

    2.- An airplane passenger carries a 230 N suitcase up the stairs, a distance of 4.2 meters along the staircase (assume a 40 degree angle for the staircase).
    a. How much work does the passenger do?
    b. The same passenger disembarks and carries the suitcase back down the stairs. How much work does the passenger do on the way down?
    c. Assume that the trip up the steps took 8 seconds. How much power did the passenger create in watts AND in horsepower on the way up?
  2. jcsd
  3. Jan 9, 2008 #2


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