Acceleration of gravity , from a pendulum

[th3plan]

Homework Statement

A space explorer lands on a new plant, and he wants to determin the gravity on it. He makes a pendulum with a lengh of 800 mm and he observes it does 24 full swings in 1min and 20 seconds. What is the acceleration of gravity to be from this ?

The Attempt at a Solution

period
=2pie multiplied by square root of (lenth of the pendulum over gravity.

period= 80/24=3.333333. gravity = 2.8

Is this right what i did, any help would be great

 

[Hootenanny]

Yes, your answer is correct.

 

[HallsofIvy]

Well, you are going to have to explain more exactly what you did.

You have determined that 2\pi \sqrt{800/g}= 10/3. Now, exactly how did you solve that equation for g? Also, what units is your answer in? I hate to disagree with Hootenanny but your answer makes no sense until you say what the units are.

(That's not true- I love to disagree with Hootenanny!)

 

[Hootenanny]

In light of HoI's post, I'm assuming that your in S.I. units.

 

[th3plan]

well i use equation T=2pi sqrt( L/g) =T and T is 10/3, so i solved for g, since i know the Lengh is 801m, then i got it to meters