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You might challenge the assertion that batteries are inexpensive energy converters. Calculate the price per kWh for a 12-volt automobile battery with a 50 amp-hour capacity that sells for 40$. If its weight is 45 lb, what is the energy density in watt-hours per lb

Respuesta :

Answer:

The price per kWh is [tex]c = \$ 66.67[/tex]

The energy density in watt-hours per lb is [tex]Z = 13.33 \ Wh /lb[/tex]

Explanation:

From the question we are told that

 The voltage of the battery is  [tex]V = 12 \ V[/tex]

 The capacity of the battery is  [tex]I t = 50 \ amp \cdot hour[/tex]

 The  price is  [tex]C = \$ 40[/tex]

 The weight of the battery  is  [tex]W = 45 lb[/tex]

Generally the energy generated by the battery is mathematically represented as

         [tex]E = P * t[/tex]

Here  P is power which is represented as

        [tex]P = I V[/tex]

So

     [tex]E = IV * t[/tex]

=>   [tex]E = It * V[/tex]

=>   [tex]E =50 * 12[/tex]

=>   [tex]E =600 \ W h[/tex]

converting to  kW h

=>   [tex]E =\frac{600 }{1000}[/tex]      

=>   [tex]E = 0.6 \ kWh[/tex]  

Generally the cost of this energy produced is  [tex]C = \$ 40[/tex]  Hence the cost of  1 kWh  is mathematically represented as

      [tex]c = \frac{C}{ E}[/tex]

=>   [tex]c = \frac{40}{ 0.6}[/tex]

=>   [tex]c = \$ 66.67[/tex]

Generally the energy density is mathematically represented as

       [tex]Z= \frac{E}{W}[/tex]

=>    [tex]Z = \frac{600}{45}[/tex]

=>    [tex]Z = 13.33 \ Wh /lb[/tex]