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IsTim
 3 years ago
In Part A, you determined that the heat added to the coffee is what you got. If it takes 4.2 J of energy to raise the temperature of 1.0 mL of coffee by 1.0∘C, then it should take twice as much energy to raise the temperature of 2.0 mL of coffee by 1.0∘C, or to raise the temperature of 1.0 mL of coffee by 2.0∘C. Multiply carefully to find the total amount of energy needed to raise the temperature of 200 mL of coffee by the required number of degrees.
IsTim
 3 years ago
In Part A, you determined that the heat added to the coffee is what you got. If it takes 4.2 J of energy to raise the temperature of 1.0 mL of coffee by 1.0∘C, then it should take twice as much energy to raise the temperature of 2.0 mL of coffee by 1.0∘C, or to raise the temperature of 1.0 mL of coffee by 2.0∘C. Multiply carefully to find the total amount of energy needed to raise the temperature of 200 mL of coffee by the required number of degrees.

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IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0This is a hint to an assignment I am currently doing.

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0I haven't read thru the textbook much or my notes; I'ved tried, and instead made a formula sheet, although I don't know what formula to apply to this.

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1use \[E = mc \theta \] Since there r lot of data this one can be use easily ... I think u should be familiar with this...

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0Actually, haven't seen this in my formula sheet. But I'll try it out.

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1wt's the value of "required no.of degrees" mentioned in the question ?

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1then I think u can use a relationship with ratios to solve this one cause the problem says "Multiply carefully to find " which mean question doesn't expect use of any formula instead it expect to build the answer from given data... change of 1 degree in 1ml = 4.2 J change of 1 degree in 2ml = 8.4 J change of 1 degree in 200 ml = 8.4*100 J

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0These are the answers that I gave to the work, which it stated was incorrect. It requires 3 significant figures. Submitted Answers ANSWER 1: Deduction: 3% "what you get" = 8.4⋅102 J ANSWER 2: Deduction: 3% "what you get" = 8.40⋅102 J

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0the 102 is suppose to be 10^2

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0So yes, I did use your answer, but apparently it was incorrect here.

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1It requires 3 significant figures. = is it same for the 840 J ?

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0wouldn't 8.40*10^3 J have worked?

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0Because 840 is only 2 sig digs without using a decimal point

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1no .. I just told that 'cause it's the same answer I get even if I use E = mc*theta

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0So, both answers would be considered incorrect with this question then?

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1@ganeshie8 , @thomaster

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0I managed to get the question after that correct, if it helps at all.

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1if 840 J is wrong .... there is one possible reason: we calculate 840 J to a temp. change of 1 degree. But the question asks the energy need for a temp. change of required no. of degrees. And we assume that is also as 1 degree. But this question has a section name part A. Does that part mention about some reading of temperature regarding this coffee cup

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0Yes. This is a 'hint' to a larger question.

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0Suppose that you have left a 200mL cup of coffee sitting until it has cooled to 30∘C , which you find totally unacceptable. Your microwave oven draws 1100 W of electrical power when it is running. If it takes 45 s for this microwave oven to raise the temperature of the coffee to 60∘C , what is the efficiency of heating with this oven? Find the efficiency e of the oven. You will need to use the fact that 4.2 J of energy is required to raise the temperature of 1.0 mL of coffee by 1.0∘C .

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1yo ... that's the missing point!

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1the temperature of the coffee cup was 30 degree at the beginning and it has to be increased up to 60 degree

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0But I dunno if those 2 questions are directly related/

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1So we must calculate energy need to change the heat of 200ml by 30 degree

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1not just by one degree which is 840 J instead it should be 8.4*30 * 100 J which is 252*100 J and it also satisfy the condition of 3 digit ... try that one!

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0I've got 2 tries left. i'll test it out

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0err sorry. i'm asking this question on several different mediums, and i'm just 'cross referencing'

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0Err, 8.4*30 * 100 J looks like \[8.4*10*100\] 252*100 J looks like \[252*100\]

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0Because if that was true, wouldn't that make the question incorrect?

***[ISURU]***
 3 years ago
Best ResponseYou've already chosen the best response.1srry.. could u explain it more ... it's not clear

IsTim
 3 years ago
Best ResponseYou've already chosen the best response.0The stars; do they represent the 'multiply' or the 'exponent' function?
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