Answer:
995 N
Explanation:
Weight of surface, w= 4000N
Gravitational constant, g, is taken as 9.81 hence mass, m of surface is W/g where W is weight of surface
m= 4000/9.81= 407.7472
Using radius of orbit of 6371km
The force of gravity of satellite in its orbit, 
Where 
and 
F= 995.01142 then rounded off
F=995N
'Frequency' is a word that often confuses some people ... for no good reason.
It just means "frequent-ness" or "often-ness" ... how often something happens.
The SI unit of frequency is the Hertz (Hz). Hz means 'per second'.
So " 13 Hz " means 13 per second.
Here are examples of frequency:
-- 780 kilohertz (on your AM radio dial)
-- 98.7 Megahertz (on your FM dial)
-- 5.8 Gigahertz
-- twice a day
-- three per week
-- every 6 months
For the "what is this investigation about", you could pick
the shape of the Earth, the size of the Earth, how the Sun
generates its energy, the distance to the Moon, why the
sky is blue ... things like that. There are millions uvum.
Trustworthy sources of information:
-- an Encyclopedia
-- a library book that's all about the subject of the investigation
-- a magazine that's all about exactly the subject of the investigation
-- a TV program that's ALL ABOUT the subject of the investigation
-- a teacher who teaches the subject of the investigation
-- a high school student whose hobby is the subject of the investigation
-- an adult whose hobby is the subject of the investigation
-- an adult whose JOB is the subject of the investigation
-- a high school student who got a very good grade in a course
where the subject of the investigation was taught
-- a college student who is studying the same subject as the investigation
UN-trustworthy sources of information:
(This doesn't mean that they're always wrong. It means that
they can tell you something, and you just can't be sure of
whether it's right or wrong.)
-- some sources listed on Google
-- some YouTube videos
-- other students in your class
-- other students at your school
-- your next-door neighbor (unless he's on the 'trustworthy' list above)
-- a newspaper article
-- a TV news item, or a TV program that's NOT all about the subject
-- a public opinion poll; (just because everybody thinks so
doesn't mean that it's true)
-- your sister's friend's hairdresser's grocer's mother-in-law
-- anything you hear if you don't know WHO said it
Explanation:
Plate tectonics is the idea that the earth's outer solid crust (the lithosphere) is fragmented into a few dozen "plates" that pass relative to each other across the earth's surface, like ice slabs on a lake.
A scientist named Alfred Wegener in 1915 proposed that the continents rammed through ocean basin crust, which would clarify why the shapes of many coastlines (such as South America and Africa) seem to match together like a puzzle.
Ohm's law states that the voltage within an electrical circuit is equal to the product of the current and the voltage. Mathematically it is written as V=IR where V is the voltage, I is the current and R is the resistance. If a circuit has a voltage of 9.0 Volts and a resistance of 36.0 Ohms, the current is I = V / R = 9.0/36.0 = 0.25 Amps.
