An electric clothes dryer draws 15 A at 220 V. If the clothes put into the dryer have a mass of 7.0 kg
when wet and 4.0 kg dry, how long does it take to dry the clothes? (Assume all heat energy goes into
vaporizing water, Lv = 2.26 ´ 106 J/kg).
a. 55 min
b. 34 min
c. 20 min
d. 16 min


Sagot :

Answer:

Explanation:

7.0 - 4.0 = 3.0 kg water

3.0 kg(2.26 x 10⁶ J/kg = 6.78 x 10⁶ J

220 V(15 A) = 3300 W

1 W = 1 J/s

6.78 x 10⁶ J / 3300 J/s = 2054 s

2054 s / 60 s/min = 34 min

It will take  b)  34 min to dry the clothes

What is an electrical energy ?

An electric energy is amount of work done or energy consumed in a given amount of time

water absorbed by wet cloth = mass when it was wet - mass when dried

                                                    7 - 4 = 3 kg

latent heat of vaporization = 2.26 * 10 ^6 j/kg

To vapor 3kg water heat required = 3 * 2.26 * 10 ^6 j/kg = 6.78 * 10 ^ 6 j/kg

Power = voltage * current

              220 * 15 = 3300 W

energy = power * time

time = energy / power

       =  6.78 * 10 ^ 6 j/kg /3300 W

       = 2054.54 sec

or 2054.54 / 60 = 34 min (app)

It will take  b)  34 min to dry the clothes

learn more about electrical energy

https://brainly.com/question/14667454?referrer=searchResults

#SPJ2