physics question (1 Viewer)

[lazyandcool]

if mass of object(kg)=1.99 X 10^30
diameter(km)=1 392 530km
what is the gravitational acceleration of this planet

 

[khorne]

F of an object = mg
F between them = m1m2G/d^2

mg = m1m2G/d^2

g = m2G/d^2

fill in the blanks

btw the 2/1s are subscripts

 

[changeofheart]

Actually..

g (gravitational acceleration) is given by the formula of g= GxM/r^2

where G= universal gravity constant 6.67 x 10^-11
M = mass of planet in kg
r= radius of planet in metres

if mass of object(kg)=1.99 X 10^30
diameter(km)=1 392 530km
what is the gravitational acceleration of this planet
so g = (6.67x10^-11 x 1.99 x 10^30) / (1392530 x 10^3)^2
= 68.45 ms^-2

 

[khorne]

Don't remember formulas dumbarse lol...derive them like I did. it only requires basic knowledge and is much more useful

 

[changeofheart]

I only learn to derive equations where needed in accordance to the syllabus
plus, you derived it wrong..

also, g is independent of the minor body's mass

 

[khorne]

how the fuck did I derive it wrong...it's central body, g2 * G/d^2 (distance from centre of body to point) it's most certainly correct, dumbshit unsavoury character.

 

[changeofheart]

You got it wrong again

The force of gravity between a minor body and a celestial body is mg=GxMxm/ r^2, not 2GxMxm/r^2

Ultimately, arguing on the basis of a factually incorrect judgment can only get you so far
Persian dirt ! sorry for your plummeting rug trade business

 

[khorne]

dude I said those are subscripts you fucking retard devoid of any ability to read not very nice person.

 

[changeofheart]

But still pertaining to the wrong use of formula!
You two faced nut head

 

[FCB]

Alright the answer given i believe is wrong
Gm/r^2

((6.67x10^11)(1.99x10^30))/(696265000)^2

Answer is 273ms^-1

 

[FCB]

Don't remember formulas dumbarse lol...derive them like I did. it only requires basic knowledge and is much more useful

Dont need to memorise do rerive, use the formula sheet.

I only learn to derive equations where needed in accordance to the syllabus
plus, you derived it wrong..

also, g is independent of the minor body's mass

As true as that is, the minor mass plays a role but for simplicity sake, we dont use it.

 

[khorne]

The mass of the object doesn't have any impact on g, retard. If you dropped a hammer and feather on the moon, they'd fall at the same rate...g/m/s/s

 

[FCB]

The mass of the object doesn't have any impact on g, retard. If you dropped a hammer and feather on the moon, they'd fall at the same rate...g/m/s/s

Maybe not a hammer but a satellite in orbit but you neglect that. Anyways...

 

[lazyandcool]

Thanks all.My physics teacher sux

 

[khorne]

Hey, FCB, you should be a doctor...they say laughter is the best medicine, and you're a fucking joke

 

[hscishard]

Alright the answer given i believe is wrong
Gm/r^2

((6.67x10^11)(1.99x10^30))/(696265000)^2
Answer is 273ms^-1

pretty sure that's the correct answer

 

[FCB]

Honestly Khourne, I think you may have misunderstood me, a satellite of 1000kg is not going to effect the value of g and thus they neglect it. Thats the whole basis of Newtons Law of Universal

 

[FCB]

pretty sure that's the correct answer

I just re-read that post and that's the answer I got but it's supposed to be ms^-2 and when I said 'the given answer I believe is wrong' was reference to the post above the my original post.

That probably made no sense

 

[Drongoski]

I just re-read that post and that's the answer I got but it's supposed to be ms^-2 and when I said 'the given answer I believe is wrong' was reference to the post above the my original post.

That probably made no sense

Don't know what's going on. But unit of acceleration must be ms^-2 and not ms^-1

 

[Aquawhite]

Just to chime in on this, sort of related to the question that khorne commented about remembering formulae. You are given a huge data/formula sheet in the Physics exam so you should only need to briefly know what the equations look like, but it is greater skill to know how to equate equations and solve them by derivation - some questions require this (without explicit mention in the syllabus).

Also, the personal insults end now - stop being passive aggressive, khorne.