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Andrew
Andrew asked in Science & MathematicsPhysics · 4 weeks ago

Physics HW?

Consider a 2.75-W electric clock. 

A.) What is the yearly cost, in dollars, of operating such a clock if the cost of electricity is $0.085 per kW⋅h ? 

4 Answers

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  • Philomel
    Lv 7
    4 weeks ago

    8760 hr/yr*2.75 w=24,090 wh/1000=24.09Kwh

    24.09*.085=~$2.05/yr.

  • ?
    Lv 7
    4 weeks ago

    n = 24*365  hours 

    cost = 2.75/1000*n = 24*365*2.75/1000*0.085  = 2 $ ; 5 cents per year

  • ?
    Lv 7
    4 weeks ago

    Given 2.75w, start there and apply converters:

    2.75 w (1kw/1000w) ($0.085/kW⋅h) (24hr/day) (365.25 day/yr) = $2.0490525/yr

    Rounds to $2.05/yr

    Source(s): Use Unit Cancellation (Dimensional Analysis) to work problems. If you don't know this technique, watch the video attached, only takes 7 minutes and is KEY to working many real-world, science, and chemistry problems! General: https://www.youtube.com/watch?v=HRe1mire4Gc
  • ?
    4 weeks ago

    $7.45 as 0.00085*24*365

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