space dot pt help (1 Viewer)

[Dave85]

hey,

there are these3 dot points that we never got taught very well and if u cud help i'd REALLY appreciate it. They're all from part 3 of space:

*discuss factors affecting the strength of gravitational force

*discuss the importance of Newtons lasw of universal gravitation in understanding and calculating the motion of satelites

*describe a gravitational feild in the region surrounding a massive object in terms of its effects on other masses in it

Any help wud be great. THX in advance

 

[nero_46]

Follow the link:

http://www.hsc.csu.edu.au/physics/core/space/9_2_3/923net.html

all the info is there.

 

[Dave85]

thx but ive already looked there and the info isnt that in-depth. I was hoping someone might have something a little more detailed and a better explanation

 

[Rahul]

it is very hard, because this is from section 3, which was changed entrirely after the ammendment. so most people wouldnt have even covered it in class, like me.

the best bet would be do use the old syllabus texts, i'm sure there will be some in the local library, and make notes using that. keep refering back to the csu site to make sure you are on the right track.

i havent done this section yet, so i can't directly help you. if i cover it and the thread is still around, i'll post it up.

 

[Constip8edSkunk]

gravity has infinite range, is an attractive force
inversely proportional 2 distance squared
proportional to mass of objects concerned
higher orbit longer period for the satellite, etc ...just derive/link it with the newtons law and circular motion eqns

 

[+:: $i[Q]u3 ::+]

sorry i coulnd't be bothered looking at the link so if this is what's in the link then i'm sorry.. i just can't be stuffed openin anobther window ^^

factors affecting strength of grav. force
-planet
-altitude (higher, less g)
-location on earth - g is greater at poles (earth is flattened) and less at equator (centrifugal effect)
also earth's crust ain't uniform, which can affect g (dense mineral deposits etc)

um.. if u equate Newton's law of grav. with centripetal force, you get an equation for the orbital velocity of a satellite. yeah it's a bs dot point.

a gravitational field is a region in which any mass will experience a gravitational force.

as i sed, sozz if u knew this already. ciaoz~

 

[deweydude]

There is kind of a cheat way in the exam if you got that question. Look at the formulae sheet, find the formula for gravitational force. Look at the variables involved, these are the things that affect gravitational force.

Also: Gravity is the only attractive force, it is the weakest force, with an infinite range. If you did Q2Q then you should have done fundimental forces again...

 

[t-i-m-m-y]

yes.. those dot points seem to be fairly mathematically orientated

heres what i quote from my study notes:
3. The Solar system is held together by gravity
3.2.1 describe a gravitational field in the region surrounding a massive object in terms of its effects on other
masses in it
Other masses within the gravitation field will experience a force of attraction. Objects in a gravitational
field will have potential energy.
3.2.2 Define Newtons Law of Universal Gravitation: F = Gm 1m2
d 2
3.2.3 Discuss the importance of Newtons Law of Universal Gravitation in understanding and calculating the
motion of satellites
Newtons Law of Universal Gravitation is important because it dictates the motion of satellites, along with
Keplers Law of periods. It enables physicists to calculate the position and velocity of the satellite
instantaneously. It also controls the motion of spacecraft traveling through the solar system.
The gravitational force of a body exerted on a satellite orbiting around it is equal to the centripetal force.
This is important because it keeps the satellite in its orbit
3.2.4 Identify that a slingshot effect can be provided by planets for space probes
A slingshot effect can be provided by planets for space probes in which the probe picks up angular
momentum and the planet loses an equal amount of angular momentum. This is caused by gravitational
attraction between the probe and the planet. This is also known as gravity-assist technique. The loss of
momentum from the planet is negligible. Using this slingshot effect, the velocity of a space probe can
be altered significantly without using much fuel.
3.3.1 Present information and use available evidence to discuss the factors affecting the strength of the
gravitational force
From Newtons Law of Universal Gravitation, the factors affecting the strength of the force are:
Ÿ Mass of the bodies
Ÿ Distance between the objects

sorry about the extra bits- no time to cut it out.. i'm sure u dont' mind

 

[t-i-m-m-y]

btw 3.3.1 is a bit ambiguios i'm not sure if it was sposed to refer to variations in g- like altitude etc

 

[Dave85]

yeah i interpreted 3.3.1 as referring to variations due to altitude etc as well but i suppose it doesnt hurt to know the dot pt from both interpretations hey... bloody ambigious syllabus dt pts!!!

 

[t-i-m-m-y]

Originally posted by Dave85
yeah i interpreted 3.3.1 as referring to variations due to altitude etc as well but i suppose it doesnt hurt to know the dot pt from both interpretations hey... bloody ambigious syllabus dt pts!!!

yeah it sorta comes in under the pendulum prac tho'