Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
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.
 6 months ago
 6 months 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.
 6 months ago
 6 months ago

This Question is Closed

IsTimBest ResponseYou've already chosen the best response.0
This is a hint to an assignment I am currently doing.
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
I 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.
 6 months ago

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

IsTimBest ResponseYou've already chosen the best response.0
Actually, haven't seen this in my formula sheet. But I'll try it out.
 6 months ago

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

***[ISURU]***Best ResponseYou've already chosen the best response.1
then 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
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
These 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
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
the 102 is suppose to be 10^2
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
So yes, I did use your answer, but apparently it was incorrect here.
 6 months ago

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

IsTimBest ResponseYou've already chosen the best response.0
wouldn't 8.40*10^3 J have worked?
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
Because 840 is only 2 sig digs without using a decimal point
 6 months ago

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

IsTimBest ResponseYou've already chosen the best response.0
So, both answers would be considered incorrect with this question then?
 6 months ago

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

IsTimBest ResponseYou've already chosen the best response.0
I managed to get the question after that correct, if it helps at all.
 6 months ago

***[ISURU]***Best ResponseYou've already chosen the best response.1
if 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
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
Yes. This is a 'hint' to a larger question.
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
Suppose 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 .
 6 months ago

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

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

IsTimBest ResponseYou've already chosen the best response.0
But I dunno if those 2 questions are directly related/
 6 months ago

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

***[ISURU]***Best ResponseYou've already chosen the best response.1
not 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!
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
I've got 2 tries left. i'll test it out
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
err sorry. i'm asking this question on several different mediums, and i'm just 'cross referencing'
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
Err, 8.4*30 * 100 J looks like \[8.4*10*100\] 252*100 J looks like \[252*100\]
 6 months ago

IsTimBest ResponseYou've already chosen the best response.0
Because if that was true, wouldn't that make the question incorrect?
 6 months ago

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

IsTimBest ResponseYou've already chosen the best response.0
The stars; do they represent the 'multiply' or the 'exponent' function?
 6 months ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.