vd4xncw8wh
contestada

Electrical power companies sell electrical energy
by the kilowatt-hour, where 1 kWh = 3.6x106 J.
Suppose that it costs $0.15 per kWh to run your
electric water heater. How much does it cost to heat
75 kg of water from 15°C to 43°C to fill a bathtub?

Respuesta :

nuralfaqih

Heat used by electric heater :

Q = m • c • ∆T

Q = (75 kg)(4200 J/kg°C)(43°C - 15°C)

Q = 8.82 × 10⁶ J

Cost of electrical energy :

Cost = (8.82 × 10⁶ J)/(3.6 × 10⁶ J) • ($ 0.15)

Cost = $ 0.3675

lhmarianateixeira

In this exercise we have to use the knowledge of heat to calculate how much this energy used will cost, so we have:

The cust to fill a bathtub will be [tex]$ 0.3675[/tex]

so organizing the information given in the statement we have that:

  • 1 kWh = 3.6x106 J.
  • costs $0.15 per kWh
  • 75 kg of water
  • 15°C to 43°C

The heat formula is given by:

[tex]Q = m * c * \Delta T[/tex]

Substituting the values ​​already given in the statement we have:

[tex]Q = (75)(4200 )(43- 15)\\Q = 8.82* 10^6 J[/tex]

So to calculate the cost we have to;

[tex]Cost = (8.82 *10^6 )/(3.6 *10^6) ( 0.15)\\Cost = $ 0.3675[/tex]

See more about heat at  brainly.com/question/1429452

Otras preguntas