All Answers

Melody:
Hi Tayfuntan,

One source of confusion is that t and T are totally different things
T is a constant and t is a variable.
131222 Latex answer integral.JPG

I then used Wolfram Alpha calculator to solve

http://www.wolframalpha.com/input/?i=solve+%2836.4%2B6*10%5E-3T-2*10%5E5*T%5E-2%29%28T-600%29+%3D94258+over+the+real+numbers

There are 4 answers.

i search to capital (T) T is degree of kelvin of my question.
And thank you so much for this answers, u saved healt of my mind

tayfuntanDec 22, 2013

+118725

Well, if you are talking about the slope of a line on a number plane, you can put a little cross on two different points on the line.
Now you can get from one point to the other by going straight up and then straight across.
Here is a picture to help you understand.

131222 slope of a line.JPG

MelodyDec 22, 2013

+118725

CPlusHRis:
11.11^11 in standard form to 4 significant figures.

why is this causing you trouble Chris, don't you understand significant figures? (You need to calculate 11.11^11 on your calculator first)

I'll give you a couple of examples
346285 = 350000 correct to 2 significant figures. This is because the first 2 nonzero numbers on the left are 34 the next one '6' is used for rounding, then the zeros are needed just to show place value.
It would probably be better to write this as 3.5 x 10 ⁵

7.00258 x 10 ^-4 = 7.0 x 10 ^-4 correct to 2 significant figures. (The zero is significant this time)

I hope that helps

MelodyDec 22, 2013

+118725

[quote="CPlusHris"][input]4.3*10^-3=10.2(sqrt(2y*(147.83-51.9[/input] Estimate the following of y correct to one significant figure without using a calculator.

I have tried several times to try and solve this. I ended up with 0.016 as an estimate using the following method.

1. Round off: 4.0* 10^-3=10(sqrt(2y*(150-50)
2. Put 4.3*^-3 into standard form: 0.0043

Working out
0.0040=10(sqrt(2y*(150-50)

0.0040=10(sqrt(2y*100)

0. 00040=(sqrt(2y*100)

0.00000016=2y*100

0.0000000008

8 * 10^(-10)

Just a couple of little errors can make a big difference!

The actual answer is 9 * 10^(-10) Correct to 1 significant figure.

So your answer (and mine) does not quite have the accuracy that you were asked for.
But I still think that it is a sensible estimate.

MelodyDec 22, 2013

+118725

CPlusHris:
Does -|-8|-|-3| evaluate to 5 or 11?

Hi CPlusHris

This is -(8) - (3) = -8-3 = -11

why don't you try this one

-|8-5|+|-6+1|=?

MelodyDec 22, 2013

+118725

Hi Tayfuntan,

One source of confusion is that t and T are totally different things
T is a constant and t is a variable.
131222 Latex answer integral.JPG

I then used Wolfram Alpha calculator to solve

http://www.wolframalpha.com/input/?i=solve+%2836.4%2B6*10%5E-3T-2*10%5E5*T%5E-2%29%28T-600%29+%3D94258+over+the+real+numbers

There are 4 answers.

MelodyDec 22, 2013

Dec 21, 2013

+118725

Please show me what you have tried.
Maybe with an attachment.

MelodyDec 21, 2013

the real answer is 4

GuestDec 21, 2013

+118725

VIPIN:
HOW TO FIND SLOPE OF TRIANGLE

Hi Vipin,
Do you want to try and re-phrase your question? It really does not make any sense at the moment.
Sorry.

MelodyDec 21, 2013

+118725

Peter A Boldtg3g:
solve the resolution of two forces acting on a point at a specific angle

Hi Peter,

You need to get the x and y components of each of the forces
Then Add the x components to get the resultant x force
Add the y components to get the resultant y force

once you have the resultant x and y forces you can then put them together to get the resultant force and angle direction.

Look at this you tube clip.

http://www.youtube.com/watch?v=e-d-aVvx5RA

MelodyDec 21, 2013

+118725

lilg96:
how much heat is required to raise the temperature of 235g of iron from 22.5 C to 234 C?

Hi Lilg
i'll will start by saying that I am no chemist.
I googled your question and the exact same question (with the answer) was in a number of places

It seems that
heat required = Mass * specific heat of iron * increase in temperature
You do need to check that the units are compatible

Depending on which web page I look at, the specific heat of iron is between 444 and 460 [J/(KgDegrees)] I don't know why the values are different.

This is a snip of an answer.
131221 heat needed for temp change.JPG
This is a 2nd answer
131221 heat needed for temp change2.JPG

There you go, take your pick.

MelodyDec 21, 2013

+118725

Mighty:
A race horse took 2 2/5 minutes to run 1 1/2 miles. How long would it take the horse to run one mile?

Hi Mighty,
There is a couple of ways to do this.
----------------------------
If you just think about the units, you want minutes/mile
So, if you take the number of minutes and divide it by the number of miles, you will have your answer.
-------------------------
another way to do it would be to realise that if you divide 1 and a half miles by 3 you get 1/2 a mile
so if you divide 2 2/5 by 3 you will find out how many miuntes to run a half mile.
What would you do then?
-----------------------

MelodyDec 21, 2013

+118725

Mighty:
A meter stick standing vertically casts a shadow 1.5 meters long on the ground. At the same time, a nearby tree casts a shadow 9 meters long on the ground. About how tall is the tree?

Hi mighty,
This is a similar triangle question. It is not particularly difficult, you don't need to use trigonometry or pythagoras or anything like that.
I want you you to try answering it yourself (Hint:draw the 2 triangles).
Get back to me with either your answer or with an explanation of what you have attempted.
That would be good.

MelodyDec 21, 2013

+118725