The burner on an electric stove has a power output of 2.0 kW. A 650 g stainless steel tea kettle is filled with 20∘C water and placed on the already hot burner. If it takes 2.70 min for the water to reach a boil, what volume of water, in cm^3, was in the kettle?

Respuesta :

Answer:

The  value is    [tex]V  =  900 \  cm^3[/tex]

Explanation:

From the question we are told that

  The  power output is  [tex]P_{out} =  2.0 \  kW  =  2.0 *10^{3} \  W[/tex]

   The  mass of the steel is  [tex]m=  650 \  g  =  \frac{650}{1000}  =  0.650 \ kg[/tex]

    The  temperature of the water is [tex]T  =  20^o C[/tex]

     The  time take is  [tex]t  =  2.70 \  minutes =  2.70 *60  = 162 \  s[/tex]

   

Generally the quantity of heat energy given out by the  electric stove is mathematically represented as

       [tex]Q =  P * t[/tex]

=>    [tex] Q =  2.0 *10^{3}  * 162[/tex]

=>     [tex] Q =  324000 \ J [/tex]

This energy can also be mathematically represented as

    [tex]Q =   \Delta T  * m  c_s *  +  m_w  * c_w *  \Delta T[/tex]

Here  [tex]c_s[/tex] is the specific heat of stainless steel with value  [tex]c_s =  450\ J/C/kg[/tex]

 tex]c_s[/tex] is the specific heat of water  with value  [tex]c_s =  4180\ J/C/kg[/tex]

  m_w is the mass of water which is mathematically represented as

      [tex]m_w  =  \rho_w  *  V[/tex]

=>   [tex]m_w  =  1000  *  V[/tex]

So

   [tex]324000 =   (100 -20 )  * 0.650  * 450 *  + 1000V * 4180 *  (100-20)[/tex]

    [tex]V  =  0.0008989 \  m^3[/tex]

converting to [tex]cm^3[/tex]

      [tex]V  =  900 \  cm^3[/tex]

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