if your computer uses 2.5A at 120V, how much will it cost to use the computer for 4 hours a day, seven days a week for two weeks? assume that the cost of electricity is $0.09 for every kWh*h of energy.
i solved it like this way could you check of i got it right plzzz??
(C= E* Charge)
to find energy E= P*t
to find power P=V*I
P=120V*2.5A=300W
NOW BACK TO FIND ENERGY
E=300W*56h(cuz 4*14)=16800W*h=16.8kW*h
C=16.8kW*h * 0,09=$1.512
therefore, it will cost $1.512
is this right??
Your calculation and approach are mostly correct! Let's go through the steps to verify your answer.
1. To find the power consumption of your computer, you correctly used the formula P = V * I, where P is power, V is voltage, and I is current. So, P = 120V * 2.5A = 300W. This means your computer uses 300 watts of power.
2. Next, to find the energy consumption, you multiplied the power by the total number of hours the computer will be used. In this case, 4 hours a day for 2 weeks (14 days) gives us 4 * 14 = 56 hours. So, E = 300W * 56h = 16800Wh.
3. Now, to convert the energy consumption to kilowatt-hours (kWh), you divided by 1000 since 1 kilowatt-hour is equal to 1000 watt-hours. So, E = 16800Wh / 1000 = 16.8 kWh.
4. Finally, to find the cost, you multiplied the energy consumption by the cost per kilowatt-hour. The cost is given as $0.09 per kWh, so C = 16.8 kWh * $0.09 = $1.51 (rounded to two decimal places).
Your final answer is very close! It should be $1.51 instead of $1.512 due to rounding.
Therefore, it will cost approximately $1.51 to use your computer for 4 hours a day, seven days a week, for two weeks at a rate of $0.09 per kilowatt-hour.