All Answers 358087 Answers

Looks like we are just adding 3/4 sequentially       n (3/4)

3 , 3 3/4,  41/2 , 5 1/4 .....etc

Again, the heat the brass ball LOSES is GAINED  by the ICE (s=2.05)and the WATER (s=4.188) that forms from the melting ice  AND some of the heat is needed to MELT the ice (Latent heat of fusion (or melting) of ice is 334 j/gm)

Brass heat loss =    300 (.38) (800- Tf)      where Tf is the final temp

Heat GAINED by ice      50 (2.05)(25)        25 is the temp change to get the ice to 0 degrees where it melts

         Melting ice             50(334)

Heat gained by the WATER (after the ice melts) =  50(4.188)(Tf)        (since the water warms from 0 degrees to Tf

now equate the losses and gains

300(.38)(800- Tf) = 50 (2.05)(25) + 50(334) + 50(4.188)(Tf)

Solve for Tf

91,200 - 114Tf = 2,562.5 +16,700 + 209.4Tf

71937.5 = 323.4 Tf

Tf = 222.44 degrees C

Thank you!

This is a simple subsitution.

3x+4y=5

2x+5y=15

To do this it is easier to use the elimination method

I multiplied the formulas buy 2 and 3 respectively to make x the common one but it can be done the other way round with y.

Anyway...

(multiply by 2)

6x+8y=10

(multiply by 3)

6x+15y=45

cancel out the x's

You get: 7y=35

Therefore y=5

Now substitute the above into the original equation...

3x+20=5

3x=-15

x=-5

Proof: -10+25=15

Eh, you're not an idiot, Mathaholic......your answers are usually pretty good.....thanks for the "stars"

ohhhh yes.

I completely forgot to times 1 by the two equations...

Im an idiot.

Anyway good working Cpill, hope you appreciate the 5 stars :)

(2x+3) / (x-4) - (2x-8) / (2x+1) =1    multiply both sides by the common denominator  of (x -4)(2x + 1)

So we have....

(2x + 3)(2x+ 1)  - [(2x - 8)(x -4)]  = (x -4)(2x + 1)   simplify

4x^2 + 8x + 3 - [ 2x^2 - 16x + 32]  = 2x^2 - 7x - 4

2x^2 + 24x  -29 =  2x^2 - 7x - 4

Subtract 2x^2 from both sides........add 7x, 29 to both sides

31x = 25      divide both sides by 31

x = 25 / 31

Please do not swear here, this forum was made for maths not swearing.

Thank you :)

By the way im back!!!

Sorry for the absence, hopefully it wont happen again until June (When i have my very important maths exam)

What you do is that you time the denominator with the number diagonally opposite.

You will get (2x+3)(2x+1)-(x-4)(2x-8)=1

It is now an wasy quadratic equation which can now be solved easily :)

You don't have to multiply probabilities for the second part because it says or. Or in a probability statement means that you add, AND means you multiply

Nice way to get to the answer.  My way of getting to the answer, completing the square, works too, but your way envolves fewer steps which I did not see.  I wish I would have thought of it first.

It would help if you gave some sort of a formula. If you do, make sure that you explain what various letters, symbols, variables stand for. For example, in your question you have(s=.385)? Does "s' stand for specific heat or what?......etc. Remember, this is a math forum and there aren't many people here who are very good at Chemistry, with a possible exception of "Alan", who is only online for a few hours a day.

I depends on the VOLTAGE and number of turns in the PRIMARY coil ....

Don't have a formula in your book relating the mass, specific heat, temperature of an element or material. Must have a chapter on it.

Yes, I do.

The heat the copper loses is GAINED by the water

specific heat of water = 4.186 j/(gm deltaT)

Let m= mass of copper

m (.385) (400-58) = 30(4.186)(58-18)   solve for m

m=  30(4.186)(40) / ((.385)(342))

m= 38.15 gm

Just curious! Wouldn't it depend on the voltage in the primary coil?

In general, when you are dealing with circles, spheres and other round objects, you use Radians. In other geometric shapes, triangles, squares, rectangles......etc., you use Degrees. Sometimes you are asked to use one or the other. Remember: 180 degrees =Pi.

They stand for "Degrees" and "Radians", which are used in measurements of angles.

If I calculated 1960, 1978 1980,1982, 1985, 1987 what is the avg

11,872/6=~1978.667

This is a composite number in the form of a semi-prime, or consisting of the product of two distinct primes:

100000 011818 183363 636536 363657 282727 273909 091063 636380 909093 = 110000 013000 001700 000190 000023 x 909090 909090 909090 909090 909091

America isn't the whole world, or the only area that counts.

250g block of cheese costs £1.80 how much is that per 100G

1.80/250 =0.72 or 72/100 of a pence-cost per gram. So,

100 x .72 =72p for 100 grams.