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# Need help with 2 questions watch

1. 1)

2)

It would be great if someone talked me through these two questions please
2. 10 pwer (watts) = energy over time

no. kilowatts = cost over cost per kilowatt hour

use the second equation to find out how many kilowatts she has,
3. FIRST QUESTION

2.5 x 20 p = 50p
£2= 50p x 4
= 4 hours

I used the 2nd equation - I found out the cost for 1 kwhand then
I found how many kwh can I do before the £2 runs out . 50p is 1 kwh, £2 is 4.

sorry if this is wrong or something,did this at the top of my head :-P
4. I still do not understand? Maybe because I am really tired and jones I don't understand the first part.

(Original post by Meghna96)
FIRST QUESTION

2.5 x 20 p = 50p
£2= 50p x 4
= 4 hours

I used the 2nd equation - I found out the cost for 1 kwhand then
I found how many kwh can I do before the £2 runs out . 50p is 1 kwh, £2 is 4.

sorry if this is wrong or something,did this at the top of my head :-P
Why did you do 2.5 x 20p? It says cost per kWh and the 2.5 is 2.5 kW? Not kWh?
5. (Original post by Susta1nz)
1)

2)

It would be great if someone talked me through these two questions please
for question 2)

think

what is a kilowatt hour - it is the work done by a 1000 W power output source for an hour

so if the work done by the wind turbine is 5600kWh over 4 hours, what is the average power output over those 4 hours?

6. (Original post by Susta1nz)
1)

2)

It would be great if someone talked me through these two questions please
for 1)

again, think, a kWh is the work done by a 1000W power output source for 1 hour

so how much time does it take for a 2,500W power output source to do the equivalent amount of work of 1kWh?

once you know that, you know for how long £2 can sustain that, given that it is 20p per kWh
7. (Original post by Susta1nz)
I still do not understand? Maybe because I am really tired and jones I don't understand the first part.

Why did you do 2.5 x 20p? It says cost per kWh and the 2.5 is 2.5 kW? Not kWh?
Oh.
not sure.

Did this in may last year so its all erased
8. (Original post by boner in jeans)
for 1)

again, think, a kWh is the work done by a 1000W power output source for 1 hour

so how much time does it take for a 2,500W power output source to do the equivalent amount of work of 1kWh?

once you know that, you know for how long £2 can sustain that, given that it is 20p per kWh
Oh my gosh, I cannot believe how stupid I can be sometimes. Thank you for help on both of these questions. Amazing Thanks alot

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