Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
- Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.
- There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:
![v = \lambda * f (1)](https://tex.z-dn.net/?f=v%20%3D%20%5Clambda%20%2A%20f%20%281%29)
- Replacing by the givens, and solving for f, we get:
![f =\frac{c}{\lambda} =\frac{3e8m/s}{0.035m} = 8.57e9 Hz (2)](https://tex.z-dn.net/?f=f%20%3D%5Cfrac%7Bc%7D%7B%5Clambda%7D%20%3D%5Cfrac%7B3e8m%2Fs%7D%7B0.035m%7D%20%3D%208.57e9%20Hz%20%282%29)
⇒ f = 8.6 Ghz (with two significative figures)
2)
- Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
![t = \frac{d}{c} = \frac{52e3m}{3e8m/s} = 17.3e-5 sec = 0.173e-3 sec = 0.173 ms (4)](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7Bd%7D%7Bc%7D%20%3D%20%5Cfrac%7B52e3m%7D%7B3e8m%2Fs%7D%20%3D%2017.3e-5%20sec%20%3D%200.173e-3%20sec%20%3D%200.173%20ms%20%284%29)
⇒ t = 0.2 ms (with two significative figures)
Answer:
A black hole is a place in space where gravity pulls so much that even light can not get out
Answer:
a) 90 kJ
b) 230.26 kJ
Explanation:
The pressure at the first point
= 10 bar —> 10 x 102 = 1020 kPa
The volume at the first point
= 0.1 m^3
The pressure at the second point
= 1 bar —> 1 x 102 = 102 kPa
The volume at the second point
= 1 m^3
Process A.
constant volume V = C from point (1) to P = 10 bar.
Constant pressure P = C to the point (2).
Process B.
The relation of the process is PV = C
Required
For process A & B
(a) Sketch the process on P-V coordinates
(b) Evaluate the work W in kJ.
Assumption
Quasi-equilibrium process
Kinetic and potential effect can be ignored.
Solution
For process A.
V=C
There is no change in volume then
![W_{a(1)}= 0\\P=10^{2}](https://tex.z-dn.net/?f=W_%7Ba%281%29%7D%3D%200%5C%5CP%3D10%5E%7B2%7D)
The work is defined by
![W_{a(2)}=\int\limits^V_V {P} \, dV](https://tex.z-dn.net/?f=W_%7Ba%282%29%7D%3D%5Cint%5Climits%5EV_V%20%7BP%7D%20%5C%2C%20dV)
║
V║limit 1--0.1
90 kJ
Process B
PV=C
By substituting with point (1) C = 10^2 x 1= 10^2
The work is defined by
![W_{b}=\int\limits^V_V {P} \, dV\\P=10^{2} V^{-1}\\ W_{b}=\int\limits^V_V {10^{2} V^{-1}} \, dV\\\\](https://tex.z-dn.net/?f=W_%7Bb%7D%3D%5Cint%5Climits%5EV_V%20%7BP%7D%20%5C%2C%20dV%5C%5CP%3D10%5E%7B2%7D%20V%5E%7B-1%7D%5C%5C%20W_%7Bb%7D%3D%5Cint%5Climits%5EV_V%20%7B10%5E%7B2%7D%20V%5E%7B-1%7D%7D%20%5C%2C%20dV%5C%5C%5C%5C)
║
ln(V)║limit 1--0.1
=230.26 kJ
In physics, there are four fundamental forces of nature – Gravitational,
Electromagnetic, Weak Nuclear, and Strong Nuclear Force. All four fundamental forces
have been interacting since the beginning of time. To answer your question “<span>All forces formed at the same time “.</span>
17.6 cm cubed all you have to do is dimensional analysis and multiply .88/1 by x/20