Garfield
-
Posts
15 -
Joined
-
Last visited
Content Type
Profiles
Forums
Events
Posts posted by Garfield
-
-
Let's say we have [math]m[/math] kg of oxygen at [math]T_1[/math] K. After heating the oxygen, it did [math]A[/math] J of work. Find the temperature to which the oxygen was heated. [math]p=const[/math]. This is all simple of course, using the [math]A=p(V_2-V_1)=\frac{m}{M}R(T_2-T_1)[/math] formula. Now we are able to find how much did [math]U[/math] change using the [math]U=\frac{3m}{2M}R(T_2-T_1)[/math] formula. Since [math]Q=U+A[/math] according to the first law of thermodynamics, [math]Q=\frac{5m}{2M}R(T_2-T_1)[/math]. Here's the problem:
[math]Q=cm(T_2-T_1)=\frac{5m}{2M}R(T_2-T_1)[/math]
from witch
[math]c=\frac{5R}{2M}[/math]. Numbers don't show that the given formula is correct nor is it correct when we take [math]V=const, c=\frac{3R}{2M}[/math]. So, my question is: Why is the above all wrong, and how do you calculat c with ideal gases and how to make a small triangle appear in front of [math]T[/math]?
0 -
13- similar triangles, find k.
14- stick triangel CDB into ACD, similar triangles, find k.
0 -
Ahem...[math]
S_{triangle}=\frac{3*4}{2}=6
[/math]
Don't you just hate it when that happens when doing calculations in your head.
0 -
I came up with a cheap formula to solve the surfice of any triangle. Though I'm not sure if it is correct. I wonder if you 1337 guys could check it.*points to sig*
0 -
The thing you'll be doing in the next few minutes:
Find a 9-digit number(natural) that has exactely one 3, one 7, one 8 and no 0's in it and when 3 is deleted the number is dividable by 78. When 7 is deleted the number is dividable by 38. When 8 is deleted the number is dividable by 73.
0 -
I don't know if I understand this exrecise correctly(bad linguistic skills) but maybe this can help: [math]Q=\rho*m(T_1-T_2)[/math] and [math]N=\frac{A}{t}[/math]. So, if there's 9800kg of substance flowing through in 1h, you need [math]Q=\rho*9800(15-0) J[/math] of energy(note the K's and C's, though) and you need [math]N=\frac{\rho*9800(15-0) }{3600s}W[/math] of power, which probably is constant.
[math]\rho[/math] is the Specific Heat Capacity([math]1040\frac {J}{kg*K}[/math] in this case. I'm not sure if this is what you want.
0 -
I'm having doubts about 12.5 ft/s...
Post height = [math]H[/math]
Object height = [math]h[/math]
Shadow speed = [math]V[/math]
Object speed = [math]v[/math]
[math]\frac{H}{h}=\frac{V}{V-v} =>V=\frac{Hv}{H-h}[/math]
Then it should be [math]8.(3)\frac{ft}{s}[/math]
Is this correct?
0 -
[math]\frac{15*5}{6} = 12.5\frac{ft}{s}[/math]?
0 -
[math]F_{net} = 0N[/math] because [math]a = 0ms^{-2}[/math], the forces on the beam are [math]F_{grav}=-(F_{rope1}+F_{rope2})=9000N[/math], and the free-body diagram didn't help me either. I'm awful in physics but if someone could give me more hints...
0 -
This is a simple exercise but I can't solve it...
A 10m 9000N beam is risen up by two parallel wire ropes (a=0m/s^2), one attached to one end and the other 1m from the other end. At what force each wire rope is rising the beam? Sorry for the broken English.
0 -
4d<5p<6s<4f<5d<6p<7s<5f <6d<7p<8s<5g<6f<7d<8p
No 5s orbital? And how does the g orbital look like?
I know, I'm a new-be. We're only learning "basics" at school.
0 -
Orbitals get "filled" with electrons starting from the orbital that has the lowest energy- 1s, than 2s<2p<3s<3p<4s<3d<4p<4d(?)...
How does the "sequnce" qontinue?
0 -
Sorry if I put this in the wrong sub-forum (I don't know all the mathematical expressions because I study maths in Estonian).
Anyways...
Two dices are tossed at the same time. What are the chances that the sum of the points is atleast 4?
31/36?
0 -
Hello, I'm Garfield. I'm 16 years old and I like science.
0
Triangle ratio
in Mathematics
Posted
Quite easy to prove with similar triangles.