If the 5,500 J of sound and light is the ONLY useful output
from the phone, then the phone's efficiency is
(5,500J / 10,000J) = 0.55 = 55% .
But the test engineer forgot one little minor almost insignificant detail.
As a test engineer myself, I'd say that he needs to turn in his laptop
and soldering iron, and think about changing his career to a job for
which he may be better suited, like 8 hours a day in a highway toll-booth.
What about that little radio transmitter and receiver inside the phone,
that maintain digital RF communication with the nearest cell tower ?
Without that microscopic radio transceiver ... plus 30 or 40 apps
that are always running unless you shut them off ... the device in your
pocket is essentially a flat rock with one side that sometimes glows.
Answer:
get students and a license
Answer:
46 m at 9.5 degrees east of south
Explanation:
Answer:
A: ≤ means less than OR equal to. < only means less than
B: 9
Explanation:
A: Because it would equal 19, and 19 is EQUAL than 19. 4(5) - 1 would equal 19, which is equal to 19, and not less than. ≤ means less than or equal to. < means less than. So its not true.
B: 47 - 2, 45. Then 5 x 9 equals 45. So 5 x 9 equals 45, then add 2 would equal 47.
Hope this helps <3
Answer:
Explanation:
The electric field equation of a electromagnetic wave is given by:
(1)
- E(max) is the maximun value of E, it means the amplitude of the wave.
- k is the wave number
- ω is the angular frequency
We know that the wave length is λ = 700 nm and the peak electric field magnitude of 3.5 V/m, this value is correspond a E(max).
By definition:
![k=8.98*10^{6} [rad/m]](https://tex.z-dn.net/?f=k%3D8.98%2A10%5E%7B6%7D%20%5Brad%2Fm%5D)
And the relation between λ and f is:
The angular frequency equation is:
![\omega=2.69*10^{15} [rad/s]](https://tex.z-dn.net/?f=%5Comega%3D2.69%2A10%5E%7B15%7D%20%5Brad%2Fs%5D)
Therefore, the E equation, suing (1), will be:
(2)
For the magnetic field we have the next equation:
(3)
It is the same as E. Here we just need to find B(max).
We can use this equation:
Putting this in (3), finally we will have:
(4)
I hope it helps you!
