In doing a load of clothes, a clothes dryer uses 15 A of current at 240 V for 55 min. A personal computer, in contrast, uses 2.7 A of current at 120 V. With the energy used by the clothes dryer, how long (in hours) could you use this computer to "surf" the internet?

Available usage time for the computer = 10.185 hrs

Explanation:

for the dryer;

I = 15 A,    V=240 V  ,  t= 55min,

convert time from min to sec. t = 55*60 =3300 sec

Energy = IVt

Energy = 15*240*3300

Energy = 11,880,000 J

            =11,800 KJ

using the energy for the clothes dryer to calculate for the time spent on the computer,

Energy = IVt

for the computer;

I = 2.7A    V=120V , t=?

t=36,666.7sec

convert this value to hour by dividing by 3600

For this case we must convert 26 seconds to hours,

By definition we have to:

1 hour equals 3600 seconds.

So, if we propose a rule of three we have:

1 hour ----------> 3600 seconds

x ------------------> 26 seconds

Where the variable "x" represents the number of hours equivalent to 26 seconds:

Thus, 26 seconds equals approximately 0.0072 hours.

0.0072 hours