# physics

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#1
A mobile base station (BS) in an urban environment has a power measurement of 25 µW at 425 m. If the propagation follows an inverse cube-power law (Section 3.2.2), what is a reasonable power value, in µW, to assume 1.7 km from the BS?

0
1 month ago
#2
(Original post by flubbsy1990)
A mobile base station (BS) in an urban environment has a power measurement of 25 µW at 425 m. If the propagation follows an inverse cube-power law (Section 3.2.2), what is a reasonable power value, in µW, to assume 1.7 km from the BS?

Power is proportional to 1 / (length)^3, so basically the length^(-1/3).

1700 is 4 times bigger than 425, so…
0
1 month ago
#3
(Original post by flubbsy1990)
A mobile base station (BS) in an urban environment has a power measurement of 25 µW at 425 m. If the propagation follows an inverse cube-power law (Section 3.2.2), what is a reasonable power value, in µW, to assume 1.7 km from the BS?

What are you stuck on?

if you say x = 1700/425

you'd want 1/x3 times the power given at 425m
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#4
Im stuck on. scientific notation to two decimal places.
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1 month ago
#5
(Original post by flubbsy1990)
Im stuck on. scientific notation to two decimal places.
Oh yeah, well I think that it probably wants you to give an answer in Watts using scientific notation with one digit on the left of the decimal point and the mantissa rounded to 2 digits

so if it was 0.012321 μW
you'd put 1.23 *10-8 W

...but I think it would have been more sensible for the question to ask for significant figures really.
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