Maths.......

[Biased Opinion]

dont know if you can help me out with this one

 

Picture1.png

I like math

 

that one looks a bit more difficult, time to take a shot at it.

[smjpl]

it wants it in fraction form

 

(2.25x)/1

 

[Biased Opinion]

it wants it in fraction form

(2+1/4)x

[smjpl]

it wants it in fraction form

 

No it says height in terms of x in its simplest form.

[Thunderjolt]

Working... Haven't done maths in a year, so it may take 5 mins

 

 

Oh god, got this:

 

xincrease = 135.1x

 

Yeah, I think it's safe to say that I can't do maths anymore. Dem Logarithms mess with me.

 

area of Sphere = πr³

Area of Cylinder = πr²xh

 

This means that the volume in the sphere is 84.8x cm³ and the volume of the Cylinder is 50.3hx cm³

 

height increase = 50.3hx + 84.8x   (Heights cancel out)

general increase = 135.1x

 

I remember being so much better at this

 

 

EDIT:Just out of interest, what did the markscheme say?

EDIT 2:Need to revise for AS Physics 2 tomorrow, bye

same here, Yay AS Physics :'(

I would say, Calc the volume of the sphere. Calc the volume of the liquid. Then add and rearrange for h.

[wjdobie]

dont know if you can help me out with this one

 

--Image--

That one isn't anywhere near as bad - It's all about how the Shapes link together, so if the Radius of one shape is 2x the radius of the other, the Area should multiply by 4 If i remember correctly, and the same with volume.

[Biased Opinion]

(2.25x)/1

 

Thats just cheating and you know it.

[smjpl]

Here is the worked out version

 

Vcyl = pi*(4x)^2*h   =    pi*16*x^2*h

 

Vsph =4/3*pi*(3x)^3 = 4/3*pi*27*x^3

 

 

                   sphere                cylinder

Vtot = ((4/3*pi*27*x^3) + (pi*16*x^2*h))   =      pi*x^2((4/3*27*x)+(16*h))     (I took the common values pi and x^2 outside)

 

Vtot = pi*x^2*16*((4/3*27*x)/16+(16*h)/16)     =    pi*x^2*16*((4/3*27*x)/16)+h)

 

Now the problem is expressed as pi*r^2*h

 

Since the height has been the only value to change, the total height has now gone from h to ((4/3*27*x)/16)+h) = h + 2.25x

[Biased Opinion]

for the second one, assuming that volume and surface area is proportional to the radius of the object you should get a surface area for B of 160cm^2 and a volume for A of 300cm^3. Someone want to clarify this for me, it has been well over a year since i have actually done any meaningful maths. And to thing im doing engineering next semester.

[Bingbing10]

for the second one, assuming that volume and surface area is proportional to the radius of the object you should get a surface area for B of 160cm^2 and a volume for A of 300cm^3. Someone want to clarify this for me, it has been well over a year since i have actually done any meaningful maths. And to thing im doing engineering next semester.

i checked it and its wrong

[Biased Opinion]

Just as a piece of advice to the OP and anyone else in his situation, assuming your marking system is not completely fucked it should be possible to get almost full marks on a question without actually getting it right (has happened to me before). What really matters is how you show your understanding of the method and concepts of the question and how different concepts link together. Just getting forum people to do the questions for you will not actually get you anywhere, you need to understand what is going on within the question and what you need to do to finish it even if that question is no the same as anything you have ever seen before. If you can't do this then you will never be able to pass anything but the most basic of problems (which are probably quite similar to things that you have done in class).

[Biased Opinion]

i checked it and its wrong

back to having fun then.

[Socratic]

https://uk.answers.yahoo.com/question/index?qid=20090326112922AAhJ4xv

[Biased Opinion]

ok, so what i have figured out so far is that the base and top of the object are about 4x the surface area on object B than they are on A. No sure what the ratio for the wrap around part is though.

[Socratic]

dont know if you can help me out with this one

 

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https://uk.answers.yahoo.com/question/index?qid=20090516100418AAa4T78

[old reece frost]

I've also got a GCSE maths exam tomorrow, good luck

[Bingbing10]

https://uk.answers.yahoo.com/question/index?qid=20090516100418AAa4T78

dunno if you can find the answer for this

[Socratic]

https://uk.answers.yahoo.com/question/index?qid=20100202111032AAsWEf8

[MrTomnus]

For my answer earlier, instead of putting h as the new height when equating the new volume, it should be (h+delta h), which will then allow you to find the answer.

[Nineshadow]

Come on,this is so easy.

[Nineshadow]

dunno if you can find the answer for this

fdgdfdfdf.png

If the two cones are similar that means that  K is the ratio of different stuff from each one.

Like :

e2 / e1 = k (e = edge)

r2 / r1 = k

 

However,the ratio of surfaces is equal to k squared.

k^2 = 64 => k = 8

r2 / r1 = 8

r2 = 8 * r1 = 8 * 10 = 80 cm

 

Easy stuff.

[Quantum]

It's simple really, what you overlooked was that you forgot to carry the 2. I know, such a common error, yet it's overlooked. Trust me on this, I am a certified teacher to teach you how to math properly. 

In all seriousness, I hope you the best of luck on your exam tomorrow and I'm too lazy to actually help (sorry). But I'm sure the people before me have helped you well enough!