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
Physical constant is constant even in strong gravitational fields
Montreal VR headset team turns to crowdfunding for Totem
Researchers study vital 'on/off switches' that control when bacteria turn deadly