View Single Post
sooperdrave
#1
Sep8-10, 11:45 PM
P: 8
1. The problem statement, all variables and given/known data

A certain power supply provides a continuous 371W to a load. It is opperating at 0.13% efficiency. In a 129 day period, how much does it cost (in dollars) to run the device if electricity costs 0.34 $ per kWh?

2. Relevant equations

im not sure..... everything has to be to 3 significant digits after the decimal.


3. The attempt at a solution

i have tried this a few different ways.... im not sure where the efficiency comes in.
this is what i did:

371W=.371kW
129days x 24= 3096hours
.371kW x 3096= 1.4932008kWh
1.4932008kWh x .34 = .507688272
answer is: $0.508
Phys.Org News Partner Science news on Phys.org
World's largest solar boat on Greek prehistoric mission
Google searches hold key to future market crashes
Mineral magic? Common mineral capable of making and breaking bonds