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Ocr gateway p1 p2 p3 15/06: Officialthread

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Original post by mxskaan
YAY! Yeah I got 540p too :smile:

1.5kw x 20hrs to get 30kwh

1 kwh = 18p so 30 x 18 = 540p yay

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I got 1080p.

It said that the average power was 1500W and she left it on for 0.5 hours. So wouldn't you need to get the power for one full hour and then multiply it by the 20 hours.

I did

1500W / 0.5 hours = 3000W

3000w = 3kW

3kW x 20h = 60kWh

60kWh x 18p = 1080p
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JustRay
Original post by LieutenantJ
I got 1080p.

It said that the average power was 1500W and she left it on for 0.5 hours. So wouldn't you need to get the power for one full hour and then multiply it by the 20 hours.

I did

1500W / 0.5 hours = 3000W

3000w = 3kW

3kW x 20h = 60kWh

60kWh x 18p = 1080p

I got 540 pence simply by doing 1500 watts = 1.5kW
1.5kW x 18 = 27
27 x 20h = 540 pence
Original post by LieutenantJ
I got 1080p.

It said that the average power was 1500W and she left it on for 0.5 hours. So wouldn't you need to get the power for one full hour and then multiply it by the 20 hours.

I did

1500W / 0.5 hours = 3000W

3000w = 3kW

3kW x 20h = 60kWh

60kWh x 18p = 1080p


Got 1080 too or something... Apparently it was in Kw and had to convert to kwh idk.
Original post by mxskaan
How did everyone find the exam??

For the calculations (as they're easy to check with others) I got:

7.83A for the highest current (oven)

2m/s^2 for acceleration
280,000J for workdone and 56,000 watts for power

Were there any more calculations?

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For the cost, I feel that it was 1080 pence because it was 1500 W for 0.5 hours, and therefore for 1 hour it would be 3000 W.
(edited 7 years ago)
Original post by Cicada3301
Got 1080 too or something... Apparently it was in Kw and had to convert to kwh idk.


Me too. How about the temperature change for the beaker and the water?
Original post by mxskaan


What was the question to the answer: 280 000 J work done?
Original post by Chittesh14
I disagree with the plastic beaker and water, I feel those were 100 and 200 degrees celsius respectively.
For the cost, I feel that it was 1080 pence because it was 1500 W for 0.5 hours, and therefore for 1 hour it would be 3000 W.


beaker was 60 for water and 40 for beaker.
Original post by Chittesh14
I disagree with the plastic beaker and water, I feel those were 100 and 200 degrees celsius respectively.
For the cost, I feel that it was 1080 pence because it was 1500 W for 0.5 hours, and therefore for 1 hour it would be 3000 W.


U can feel it was wrong but that doesnt make you right - your answers are definitely wrong


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Original post by quiiddle
U can feel it was wrong but that doesnt make you right - your answers are definitely wrong


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Lol okay, quite rude. I just said I think it was wrong, you're saying that my answers are 'definitely wrong' which is being cocky and rude. I'm trying to find out what the actual answer is and you're making it worse.
Original post by Chittesh14
I disagree. It said that the mass of the water was 0.2 kg. I'm not sure which one came first, but let's say the beaker was 40 degrees. Then, the mass of the beaker was 0.2 kg. If the SHC is J/Kg, then obviously you have to divide it or multiply it by the mass. So, you multiply the SHC by 0.2 and divide it by the total energy transferred and you should get 200.
Your mistake was that you didn't multiply it by 0.2.

I;m almost 99% sure on this.


No lol....

It was energy/0.2*4200
Original post by Chittesh14
I disagree. It said that the mass of the water was 0.2 kg. I'm not sure which one came first, but let's say the beaker was 40 degrees. Then, the mass of the beaker was 0.2 kg. If the SHC is J/Kg, then obviously you have to divide it or multiply it by the mass. So, you multiply the SHC by 0.2 and divide it by the total energy transferred and you should get 200.
Your mistake was that you didn't multiply it by 0.2.

I;m almost 99% sure on this.


You have really confused me... I got 60 and 40 as I divided energy transferred by shc*mass?
Original post by Chittesh14
I disagree. It said that the mass of the water was 0.2 kg. I'm not sure which one came first, but let's say the beaker was 40 degrees. Then, the mass of the beaker was 0.2 kg. If the SHC is J/Kg, then obviously you have to divide it or multiply it by the mass. So, you multiply the SHC by 0.2 and divide it by the total energy transferred and you should get 200.
Your mistake was that you didn't multiply it by 0.2.

I;m almost 99% sure on this.


I got 60 and 40. How would water increase by 200 when the boiling point is 100?
Original post by Chittesh14
I disagree. It said that the mass of the water was 0.2 kg. I'm not sure which one came first, but let's say the beaker was 40 degrees. Then, the mass of the beaker was 0.2 kg. If the SHC is J/Kg, then obviously you have to divide it or multiply it by the mass. So, you multiply the SHC by 0.2 and divide it by the total energy transferred and you should get 200.
Your mistake was that you didn't multiply it by 0.2.

I;m almost 99% sure on this.


I can't remember the numbers but in real life if the temperature change was 100 and 200, the water would have entirely evaporated while the plastic would have completely melted.
Original post by Chittesh14
Lol okay, quite rude. I just said I think it was wrong, you're saying that my answers are 'definitely wrong' which is being cocky and rude. I'm trying to find out what the actual answer is and you're making it worse.


Okay lol but what was said before was the actual answers


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Original post by xxKristenxx
I got 60 and 40. How would water increase by 200 when the boiling point is 100?


I honestly have no idea, maybe I read the question incorrectly for specific heat capacity of water. But, I'm still pretty certain on one of the answers being correct - 100 or 200 one of them, depends on which one I read correct.

Original post by U-GradeStudent
You have really confused me... I got 60 and 40 as I divided energy transferred by shc*mass?


Yeah, I done that but the SHC was J/Kg right? I have no idea. I am also starting to think that the answer is 60 and 40.
Original post by Chittesh14
I honestly have no idea, maybe I read the question incorrectly for specific heat capacity of water. But, I'm still pretty certain on one of the answers being correct - 100 or 200 one of them, depends on which one I read correct.



Yeah, I done that but the SHC was J/Kg right? I have no idea. I am also starting to think that the answer is 60 and 40.


I don't even know any more ;D the whole exam was a blur... You're probably right :biggrin:
Original post by leopard923
I can't remember the numbers but in real life if the temperature change was 100 and 200, the water would have entirely evaporated while the plastic would have completely melted.


Sorry, the answers at 40 and 60. I just realised I multiplied by mass by the specific heat capacity twice. ****.
Original post by U-GradeStudent
I don't even know any more ;D the whole exam was a blur... You're probably right :biggrin:


No, 40 and 60 is correct. I just realised I made a silly mistake again, ffs.
i got 28000 for the last one. There were two formulas for power.Shouldnt both formulas yield the same answer. I'm so confused!!!!!!
(edited 7 years ago)
What was the question for work done guys?

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