Simple proportionality question

[hmvince]

Hey guys, simple question really:
Given the equation

v = (Gm/r)[SUP]1/2[/SUP]

Is it wrong to say

v is inversely proportional to r

Or do you have to say

v is inverslely proportional to r[SUP]1/2[/SUP]

 

[tiny-tim]

hey hmvince!

Is it wrong to say

v is inversely proportional to r

yes!

Or do you have to say

v is inverslely proportional to r[SUP]1/2[/SUP]

you don't have to say "inverslely"!

 

[hmvince]

I thought you did have to, cos if you don't it means v increases with r, instead of v decreases with r.
Do you mean to say this?:
v is directly proportional to r^-1/₂?

Looking at your number of posts and recognitions I don't mean to say you are wrong, just trying to figure it out for myself!

 

[tiny-tim]

hi hmvince!

yes, it's always best to ask until you're sure

no point in losing even one mark in an exam by knowing the maths but not using the generally-accepted phrase!

you can say

v is proportional to r^-1/2

or

v is inversely proportional to r^1/2

or

v and r^-1/2 are proportional

or

v and r^1/2 are inversely proportional​

(and you don't need "directly", since it adds no information … but it isn't actually wrong)

 

[hmvince]

Thankyou!