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A hair dryer is rated at 1850 W. Assuming there are 30 days in a month, what is the monthly cost of using the hair dryer for an average of 14 minutes every day if you are charged 20 cents for every kW-h

Respuesta :

Answer:

[tex]TC=259\ cents[/tex]

Explanation:

Given:

power consumed by the hair dryer, [tex]\bar P=1850\ W[/tex]

daily average time of using the dryer, [tex]\bar t=14\ min[/tex]

days of use of dryer, [tex]d=30\ days[/tex]

cost of power usage, [tex]C=20\ cents\ per\ kW.h[/tex]

Now the total usage time including everyday:

[tex]t=d.\bar t[/tex]

[tex]t=30\times 14[/tex]

[tex]t=420\ min[/tex]

[tex]t=7\ hr[/tex]

Now the total power consumed in the given days:

[tex]P=\bar P\times t[/tex]

[tex]P=1850\times 7[/tex]

[tex]P=12950\ W.h=12.950\ kW.h[/tex]

Now the total cost of power usage:

[tex]TC=c\times P[/tex]

[tex]TC=20\times 12.950[/tex]

[tex]TC=259\ cents[/tex]