Pendulum gravity on X planet ratio

[missnola2a]

Homework Statement

Now you take off to an unknown planet with the same pendulum as in part (a). You measure the period of the pendulum on that planet and you find it to be twice as much compared to the one of the pendulum while on Earth. What is the ratio of ge on Earth to the gx of the unknown planet?

Homework Equations

I tried inputting arbitrary numbers and I came up with a ratio 2.585/1, but its not right,

T=2pi * sqrt (L/G)

The Attempt at a Solution

 

[Feldoh]

Can you show your attempted work? I'm getting around 2.45...

I should note that the gravity of planet x is 2.45, that is NOT the ratio the ratio of 9.8/2.45 is ~ 4.

 

[missnola2a]

I used L 10 on Earth and planet X and got T = 6.34 on earth, then doubled it and solved for X grav and got 2.4525

resulting in 2.587:1 which isn't right.

i did the same thing with L 50 on Earth and got a different ratio... ehhhkkk!

 

[ralilu]

the ratio is 4. if T = 2pi x sqrt(L/G) then 2T = 2pi x sqrt(L/(1g/4))

 

[missnola2a]

4e/1x??

or
1e/4x

 

[rock.freak667]

so if you know that


T= 2\pi \sqrt{\frac{l}{g_e}}

and

2T=2\pi \sqrt{\frac{l}{g_x}}


can you divide those two and thus get the ratio g_E/g_X?

 

[ralilu]

4e/1x??

or
1e/4x

4e:1x
It might look like a scary question but its a simple math problem and like rockfreak said you could've just divided the two (ratio just means divide) :)