8/31 appliance homework questions

Calculate how much it costs to use five common appliances that you use every day in your home for 24 hours. Please let me know the applicance, its wattage, amps and volts of each appliance and how you calculated cost. You will need to go to GRU or look at one of your electric bills.

1.  LED lamp: 3.5 V / 0.7 A / 2.4 W
2.  Vacuum: 120 V/ 12 A / 1440 W
3.  Blender: V/ A/ 450 W
4. Toaster oven: V / A / 1200 W
5. TV: V/ A/ 30 W

Okay, so according to GRU the cost of electricity per kilowatt-hour when consumption per month is between 250 and 750 kilowatt-hours, is $0.042. According to my electric bills for the last several months, this is where my average monthly electric consumption would fall. This rate does not take into consideration any charges not specifically for the electricity itself, such as taxes and surcharges, or fees for water or waste disposal. 

When such charges are taken into consideration the cost per kilowatt hour is something more like $0.143.

Below are the calculations for the cost of running each appliance for 24 hrs.

1 kWh = $0.042 or $ 0.143 (for these calculations I will use the first.)

1. LED lamp: 2.4 W * 24 hrs = 57.6 watts (57.6/1000)* 0.042 = $0.0024192
2. Vacuum: 1440 W * 24 = 34560 watts   34.56 * 0.042= $ 1.45152
3. Blender: 450 W * 24 = 10800 watts   10.8*0.042 = $ 0.4536
4. Toaster Oven: 1200 W* 24 = 28800 watts  28.8*0.042 = $ 1.2096
5. TV: 30 W* 24 = 720 watts  0.72* 0.042 = $ 0.03024

How many of those appliances can you plug into one outlet without tripping a breaker? Please do this mathematically rather than through direct experience.

Outlet = 120 V
Breaker = 20 A

1.  LED lamp: 2.4 W/ 120 = 0.02 A
2.  Vacuum: 1440 W/ 120 = 12 A
3.  Blender: 450 W/ 120= 3.75 A
4. Toaster oven:1200 W/120= 10 A
5. TV: 30 W/120 = 0.25 A

Since the limit for the outlet is 20 A,, any combination of these that exceeds that will trip the breaker. So the vacuum and the toaster oven cannot be plugged in the same outlet, as they use 22 A combined. The Vacuum, the LED lamp, the Blender, and the TV can all be used in the same outlet as they = 16.02 A, well below the limit. The toaster oven, the lamp, the blender, and the TV = 14.02 A, and so can also all be safely used. 

What is the directional relationship between charge and current?

Electric current flows from areas of high negative charge to areas of positive charge.

A/N. the link for the static electricity exercises was not working.