- mayankdevnani

A steam engine has an efficiency of 20%.It is given an energy of 1000 cal.per minute.What is the actual work done by it in joule and in calories?
a) 100 cal,800 J
b) 200 cal,873 J
c)10 cal,80 J
d)100 cal,100 J

- jamiebookeater

I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!

At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.

Get this expert

answer on brainly

SEE EXPERT ANSWER

Get your **free** account and access **expert** answers to this

and **thousands** of other questions

- mayankdevnani

- mayankdevnani

- amistre64

im not sure since we havent gone over this in my physics class yet, but i would say that 20% efficiency means that 20% of the 1000 cals are used; giving us 200 cals in the answer at least

Looking for something else?

Not the answer you are looking for? Search for more explanations.

## More answers

- anonymous

May I help?

- amistre64

please do :)

- mayankdevnani

ofcourse @SheldonEinstein

- anonymous

;) OK so first of all what @amistre64 discussed in his previous comment is very imp. to do this quest., so @mayankdevnani do you know what does efficiency mean?

- mayankdevnani

ok @amistre64 then

- mayankdevnani

yaa

- mayankdevnani

efficiency=winout/winin*100

- mayankdevnani

right @SheldonEinstein

- anonymous

Yeah or in simpler words it is : \(\large{\frac{\textbf{Output}}{\textbf{Input}}\times 100}\) it is 100%...

- mayankdevnani

yaa

- anonymous

So, what we have is output/input * 100% = 20% , correct?

- mayankdevnani

correct

- anonymous

Ok so now, let me understand the second line of the quest. , is the output = 1000 calorie ?

- mayankdevnani

yaa

- mayankdevnani

then

- mayankdevnani

@SheldonEinstein then

- anonymous

Oh sorry wait!

- mayankdevnani

yaa

- anonymous

I am getting diff. answer so I am checking it, sorry , it will require some patience.

- mayankdevnani

ok

- anonymous

Quest. is wrong

- mayankdevnani

why?? no it is right

- anonymous

Time is not given.. though if you take 1 minute it is 200 cal.

- mayankdevnani

yaa

- anonymous

See , Power = 1000 cal/minute (given)

- anonymous

use this and you will get 200 cal. as answer.

- mayankdevnani

so what's the work done?

- anonymous

W = P * time
if T = 1 second , W = P ...
that's it , find P(output) .. (using efficiency = Ouput/Input *100%) in Cal. per minute , that will be your answer

- anonymous

200 cal.... = WORK DONE

- mayankdevnani

no

- mayankdevnani

but the work done is in joule

- mayankdevnani

- mayankdevnani

- mayankdevnani

- anonymous

Is my answer correct, i.e. 200 cal, 873 J ?

- mayankdevnani

yaa

- anonymous

So where is the problem? ?? ? ?

- mayankdevnani

873 J how??

- mayankdevnani

- mayankdevnani

@SheldonEinstein how you got it 873J

- anonymous

I got 200 Cal, and it is in options, soo....

- mayankdevnani

but it's wrong

- mayankdevnani

i need solution

- mayankdevnani

can you help me @amriju

- anonymous

200 cal * 4.184 = 836 J (approx. ) not equal to 873 Joule , hence I think the options are wrong..

- mayankdevnani

no it was not wrong

- amriju

work done is 20 percnt of the energy given...thats efficiency....so per minute is 20percnt of 1000 cal...thats 200 cal...convert to joules

- mayankdevnani

so 1cal.=? j @amriju

- amriju

4.2...approx..the correct is 4.187...

- mayankdevnani

is it 4.37

- amriju

nope

- mayankdevnani

why??

- amriju

thats how it is defined...both are units...and 1 cal is defined as 4.187 joules...

- anonymous

That is what I was saying @amriju

- mayankdevnani

in my solution book...the answer is as follows-
\[\frac{20}{100}=\frac{W}{1000}=200 calorie\]
OR
\[200\times4.37=873J\]

- mayankdevnani

is that right?? @amriju and @SheldonEinstein

- anonymous

That is wrong, 1 Cal. = 4.187 Joule NOT 4.37 joule...

- mayankdevnani

ok... thnx... @SheldonEinstein and @amriju

- amriju

u may jst check on wikipedia...and its seems that none of the options are correct...the closest being 200, 837

- amistre64

just for reference
http://www.wolframalpha.com/input/?i=200+calorie+to+joule

- amistre64

if your options are truely: 200,873
then its most likely a typo and prolly meant to be read as 200,837

Looking for something else?

Not the answer you are looking for? Search for more explanations.