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#### Hamster Lord

##### Atrocity Exhibition
the thing is I never learned the formulas. the math packet I have had some stuff I had to learn. my math class was the intermediate and we never got anything done.

#### ▽

##### very differentiable
2*Pi*R for circumference, Pi*R^2 for area, D=2R

D being diameter, R for radius and ^ meaning an exponent

you're welcome

#### Solar

##### nothing ever ends
How to find the area of a circle: pi multiplied by radius squared (radius to the power of two)
Circumference: pi multiplied by diameter

Have fun

#### Hamster Lord

##### Atrocity Exhibition
no they want me to find the radius and diameter not the circumference and area

#### Solar

##### nothing ever ends
*Facepalm*

Aight buddy boy let me walk you through this step-by-step

1) Circumference = 264 ft.

Circumference = Pi X Diameter

Circumference/Pi = Diameter

Circumference divided by Pi will give you the Diameter. Divide that by 2 and you will get the radius.

Seeing it now?

#### Hamster Lord

##### Atrocity Exhibition
okay thank you batman. I get it now.

#### Solar

##### nothing ever ends
If you need help with the rest, drop me a VM B)

#### Silverslide

##### need some more candy cane
Need some help :x

Which inequality describes all of the possible values for a if is an obtuse angle and m =2a + 8? choices:
A. 41 > a > 86 B. 41 < a < 86 C. 41 > a < 86 D. 41 < a > 86 Hint

#### Taylor

##### Gold Member
pretty sure it's b.

i don't know how a is possible, c would have to be 40, max, and that yield 2(40) + 8 = 88, which isn't obtuse. d would have to be 87 min which would be 2(87) + 8 = 182, which is way more than what <FGD is in diagram.

b could, for example, be 50. 2(50) + 8 = 108. reasonable. i'd say b

#### Silverslide

##### need some more candy cane
alright cool, good looks man.

that means thanks

#### stephaknee

##### Hakuna Matata
The answer is B, but here's a better explanation:

An obtuse angle is an angle greater than 90 degrees. All angles are smaller than 180 degrees (because then it's just a straight line). So now we have two inequalities.

2(a) + 8 > 90
2(a) + 8 < 180

So now you just solve like a normal equation! Start off by subtracting 8 from both sides:

2(a) > 82
2(a) < 172

Now divide by 2!

a > 41
a < 86

#### Hero

##### See You Space Cowboy!
EDIT: Ignore this. I solved it on my own.

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#### Dogenzaka

So we just got to work in my mechanics class.

Please let me know if I have this down straight:
- Kinetic Energy is (m(v)^2)/2, and the NET Kinetic Energy = the different kinetic energies for different velocities added up together.
- The Work of ANY force can be calculated by the integral of the force vector dotted with dr (r being the displacement vector). This can then be simplified to Work of ANY force = integral (from x1 to x2) of Fx dx + integral (from y1 to y2) of Fy dy.
- The Work Energy Theorem states that the TOTAL NET WORK of a system = the change in Kinetic Energy. So Wnet = (m(vf)^2)/2) - (m(vi)^2)/2). Also, Wnet = W1 + W2 + W3, so in other words, all those integrals calculated from the individual forces' components as stated above added together.
- If a force is constant, W of that force can otherwise be stated to equal F * d * cos(theta), with d being distance and theta being the angle between the two.
- If the force is perpendicular to the displacement, its Work = 0.
- I may not be remembering this right, but if the force is antiparallel to the displacement, the Work is negative, and if the force is parallel to displacement, the Work is positive?
-To find the velocities of any of simple, falling block on an inclined plane problem, I can simply make free-body diagrams, calculate the work, and then discover the velocities.

Am I getting this right?

#### ▽

##### very differentiable
Yep dogen, all of your statements are true.

#### Dogenzaka

You can't calculate a double integral of e^y^3 dydx from x=0 to 1 and y=sqrt(x) to 1 with a normal function, can you?

It's part of my assignment but I have no idea how the bonk to integrate e^y^3

EDIT: Never mind, I reverse the order of integration by changing the limits.

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#### Blobbit

##### New member
We're doing reactions in chemistry and I don't understand what does adding heat do?

Like this: heat + NaOH ----> ?

Also, he wants us to write what kind of reaction it is. Would I just write "heat"?

EDIT: I think I figured it out. Is it a decomposition reaction?

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#### Victor

##### into the night for once
I am assuming your Chemistry teacher wants to know if it is a Physical or Chemical change, ask him exactly what he expects from you for that though as it isn't very specific.

The product would depend on the other reactant(s) aside from heat in the formula.

For your specific example check: Sodium hydroxide - Wikipedia, the free encyclopedia

#### Blobbit

##### New member
I think that what my teacher wants me to do is the one on this question, like the one where it says "heating CuCO3", because heat+CuCO3 is one of the questions on my worksheet too. And he wants us to name what kind of reaction it is like single displacement, double displacement, combustion, synthesis, decomposition, etc. I don't really get how you get CO2+CuO from adding heat to CuCO3 though.

#### ChaoticHeart

##### New member
I think that what my teacher wants me to do is the one on this question, like the one where it says "heating CuCO3", because heat+CuCO3 is one of the questions on my worksheet too. And he wants us to name what kind of reaction it is like single displacement, double displacement, combustion, synthesis, decomposition, etc. I don't really get how you get CO2+CuO from adding heat to CuCO3 though.

Are you missing a catalyst?

#### Blobbit

##### New member
To be honest I have no idea...I'm just starting to learn this stuff and what my teacher basically does is throw new stuff at us without really explaining anything and gets us to figure it out for ourselves :V

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