Answer:
778.4°C
Explanation:
I = 700
R = 6x10⁻⁴
we first calculate the rate of heat that is being transferred by the current
q = I²R
q = 700²(6x10⁻⁴)
= 490000x0.0006
= 294 W/M
we calculate the surface temperature
Ts = T∞ + ![\frac{q}{h\pi Di}](https://tex.z-dn.net/?f=%5Cfrac%7Bq%7D%7Bh%5Cpi%20Di%7D)
Ts = ![30+\frac{294}{25*\frac{22}{7}*\frac{5}{1000} }](https://tex.z-dn.net/?f=30%2B%5Cfrac%7B294%7D%7B25%2A%5Cfrac%7B22%7D%7B7%7D%2A%5Cfrac%7B5%7D%7B1000%7D%20%20%7D)
![Ts=30+\frac{294}{0.3928} \\](https://tex.z-dn.net/?f=Ts%3D30%2B%5Cfrac%7B294%7D%7B0.3928%7D%20%5C%5C)
![Ts =30+748.4\\Ts = 778.4](https://tex.z-dn.net/?f=Ts%20%3D30%2B748.4%5C%5CTs%20%3D%20778.4)
The surface temperature is therefore 778.4°C if the cable is bare
Answer:
a) V = 0.354
b) G = 25.34 GPA
Explanation:
Solution:
We first determine Modulus of Elasticity and Modulus of rigidity
Elongation of rod ΔL = 1.4 mm
Normal stress, δ = P/A
Where P = Force acting on the cross-section
A = Area of the cross-section
Using Area, A = π/4 · d²
= π/4 · (0.0020)² = 3.14 × 10⁻⁴m²
δ = 50/3.14 × 10⁻⁴ = 159.155 MPA
E(long) = Δl/l = 1.4/600 = 2.33 × 10⁻³mm/mm
Modulus of Elasticity Е = δ/ε
= 159.155 × 10⁶/2.33 × 10⁻³ = 68.306 GPA
Also final diameter d(f) = 19.9837 mm
Initial diameter d(i) = 20 mm
Poisson said that V = Е(elasticity)/Е(long)
= - <u>( 19.9837 - 20 /20)</u>
2.33 × 10⁻³
= 0.354,
∴ v = 0.354
Also G = Е/2. (1+V)
= 68.306 × 10⁹/ 2.(1+ 0.354)
= 25.34 GPA
⇒ G = 25.34 GPA
Answer:
a)
, b)
,
,
, c)
,
,
, ![\Delta t_{mean} = \frac{1 + \sqrt{2} }{6000}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmean%7D%20%3D%20%5Cfrac%7B1%20%2B%20%5Csqrt%7B2%7D%20%7D%7B6000%7D%5C%2Ch)
Explanation:
a) The total number of users that can be accomodated in the system is:
![n = \frac{10\,km^{2}}{1\,\frac{km^{2}}{cell} }\cdot (100\,\frac{users}{cell} )](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7B10%5C%2Ckm%5E%7B2%7D%7D%7B1%5C%2C%5Cfrac%7Bkm%5E%7B2%7D%7D%7Bcell%7D%20%7D%5Ccdot%20%28100%5C%2C%5Cfrac%7Busers%7D%7Bcell%7D%20%29)
![n = 1000\,users](https://tex.z-dn.net/?f=n%20%3D%201000%5C%2Cusers)
b) The length of the side of each cell is:
![l = \sqrt{1\,km^{2}}](https://tex.z-dn.net/?f=l%20%3D%20%5Csqrt%7B1%5C%2Ckm%5E%7B2%7D%7D)
![l = 1\,km](https://tex.z-dn.net/?f=l%20%3D%201%5C%2Ckm)
Minimum time for traversing a cell is:
![\Delta t_{min} = \frac{l}{v}](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmin%7D%20%3D%20%5Cfrac%7Bl%7D%7Bv%7D)
![\Delta t_{min} = \frac{1\,km}{30\,\frac{km}{h} }](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmin%7D%20%3D%20%5Cfrac%7B1%5C%2Ckm%7D%7B30%5C%2C%5Cfrac%7Bkm%7D%7Bh%7D%20%7D)
![\Delta t_{min} = \frac{1}{30}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmin%7D%20%3D%20%5Cfrac%7B1%7D%7B30%7D%5C%2Ch)
The maximum time for traversing a cell is:
![\Delta t_{max} = \frac{\sqrt{2}\cdot l }{v}](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmax%7D%20%3D%20%5Cfrac%7B%5Csqrt%7B2%7D%5Ccdot%20l%20%7D%7Bv%7D)
![\Delta t_{max} = \frac{\sqrt{2} }{30}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmax%7D%20%3D%20%5Cfrac%7B%5Csqrt%7B2%7D%20%7D%7B30%7D%5C%2Ch)
The approximate time is giving by the average of minimum and maximum times:
![\Delta t_{mean} = \frac{1+\sqrt{2} }{2}\cdot\frac{l}{v}](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmean%7D%20%3D%20%5Cfrac%7B1%2B%5Csqrt%7B2%7D%20%7D%7B2%7D%5Ccdot%5Cfrac%7Bl%7D%7Bv%7D)
![\Delta t_{mean} = \frac{1 + \sqrt{2} }{60}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmean%7D%20%3D%20%5Cfrac%7B1%20%2B%20%5Csqrt%7B2%7D%20%7D%7B60%7D%5C%2Ch)
c) The total number of users that can be accomodated in the system is:
![n = \frac{10\times 10^{6}\,m^{2}}{100\,m^{2}}\cdot (100\,\frac{users}{cell} )](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7B10%5Ctimes%2010%5E%7B6%7D%5C%2Cm%5E%7B2%7D%7D%7B100%5C%2Cm%5E%7B2%7D%7D%5Ccdot%20%28100%5C%2C%5Cfrac%7Busers%7D%7Bcell%7D%20%29)
![n = 10000000\,users](https://tex.z-dn.net/?f=n%20%3D%2010000000%5C%2Cusers)
The length of each side of the cell is:
![l = \sqrt{100\,m^{2}}](https://tex.z-dn.net/?f=l%20%3D%20%5Csqrt%7B100%5C%2Cm%5E%7B2%7D%7D)
![l = 10\,m](https://tex.z-dn.net/?f=l%20%3D%2010%5C%2Cm)
Minimum time for traversing a cell is:
![\Delta t_{min} = \frac{l}{v}](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmin%7D%20%3D%20%5Cfrac%7Bl%7D%7Bv%7D)
![\Delta t_{min} = \frac{0.01\,km}{30\,\frac{km}{h} }](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmin%7D%20%3D%20%5Cfrac%7B0.01%5C%2Ckm%7D%7B30%5C%2C%5Cfrac%7Bkm%7D%7Bh%7D%20%7D)
![\Delta t_{min} = \frac{1}{3000}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmin%7D%20%3D%20%5Cfrac%7B1%7D%7B3000%7D%5C%2Ch)
The maximum time for traversing a cell is:
![\Delta t_{max} = \frac{\sqrt{2}\cdot l }{v}](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmax%7D%20%3D%20%5Cfrac%7B%5Csqrt%7B2%7D%5Ccdot%20l%20%7D%7Bv%7D)
![\Delta t_{max} = \frac{\sqrt{2} }{3000}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmax%7D%20%3D%20%5Cfrac%7B%5Csqrt%7B2%7D%20%7D%7B3000%7D%5C%2Ch)
The approximate time is giving by the average of minimum and maximum times:
![\Delta t_{mean} = \frac{1+\sqrt{2} }{2}\cdot\frac{l}{v}](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmean%7D%20%3D%20%5Cfrac%7B1%2B%5Csqrt%7B2%7D%20%7D%7B2%7D%5Ccdot%5Cfrac%7Bl%7D%7Bv%7D)
![\Delta t_{mean} = \frac{1 + \sqrt{2} }{6000}\,h](https://tex.z-dn.net/?f=%5CDelta%20t_%7Bmean%7D%20%3D%20%5Cfrac%7B1%20%2B%20%5Csqrt%7B2%7D%20%7D%7B6000%7D%5C%2Ch)
A persuasive speech is structured like an informative speech. It has an introduction with an attention-getter and a clear thesis statement. It also has a body where the speaker presents their main points and it ends with a conclusion that sums up the main point of the speech.