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- Communication with satellites
Satellites may be used to transmit information over large distances.
Global wireless communication relies on satellites. Here,
ground stations transmit to orbiting satellites that amplify thesignal and retransmit it back to earth. Satellites will move
across the sky unless they are in
geosynchronous
orbits , where the time for one revolution about the
equator exactly matches the earth's rotation time of one day.TV satellites would require the homeowner to continually adjust
his or her antenna if the satellite weren't in geosynchronousorbit. Newton's equations applied to orbiting bodies predict
that the time
for one orbit is related to distance from the earth's center
as
where
is the
gravitational constant and
the earth's mass.
Calculations yield
, which corresponds to an altitude of
. This altitude greatly exceeds that of the
ionosphere, requiring satellite transmitters to use frequenciesthat pass through it. Of great importance in satellite
communications is the transmission delay. The time forelectromagnetic fields to propagate to a geosynchronous
satellite and return is 0.24s, a significant delay.
In addition to delay, the propagation attenuation
encountered in satellite communication far exceeds whatoccurs in ionospheric-mirror based communication. Calculate
the attenuation incurred by radiation going to the satellite(one-way loss) with that encountered by Marconi (total going
up and down). Note that the attenuation calculation in theionospheric case, assuming the ionosphere acts like a
perfect mirror, is not a straightforward application of the
propagation
loss formula .
Transmission to the satellite, known as the uplink,
encounters inverse-square law power losses. Reflecting offthe ionosphere not only encounters the same loss, but twice.
Reflection is the same as transmitting exactly what arrives,which means that the total loss is the
product of the uplink and downlink losses. The
geosynchronous orbit lies at an altitude of
. The ionosphere begins at an altitude of about
50km. The amplitude loss in the satellite case is
proportional to
;
for Marconi, it was proportional to
.
Marconi was
very lucky.
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Questions & Answers
differentiate between demand and supply
giving examples
differentiated between demand and supply using examples
Lambiv
how is the graph works?I don't fully understand
hi guys good evening to all
Lambiv
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline.
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
Can I ask you other question?
Shukri
What is different between quantity demand and demand?
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
how do you save a country economic situation when it's falling apart
what is the difference between economic growth and development
Economic growth as an increase in the production and consumption of goods and services within an economy.but
Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
production function means
Jabir
What do you think is more important to focus on when considering inequality ?
any question about economics?
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
Awais
thank you so much 👍 sir
Asui
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has
The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50.
A,Calculate quantities of x and y which maximize utility.
B,Calculate value of Lagrange multiplier.
C,Calculate quantities of X and Y consumed with a given price.
D,alculate optimum level of output .
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
What is the difference between perfect competition and monopolistic competition?
Mohammed
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Source:
OpenStax, Fundamentals of electrical engineering i. OpenStax CNX. Aug 06, 2008 Download for free at http://legacy.cnx.org/content/col10040/1.9
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