If the period of a pendulum is 2.0 seconds and the acceleration due to gravity is 9.8 meters/second^2, What is the length of the cord on the pendulum?
A)1.0 meters
B)0.67 meters
C)1.3 meters
D)3.5 meters

Question

If the period of a pendulum is 2.0 seconds and the acceleration due to gravity is 9.8 meters/second^2, What is the length of the cord on the pendulum?
A)1.0 meters
B)0.67 meters
C)1.3 meters
D)3.5 meters

anonymous · Answer

can you help me

theeric · Answer

Are you speaking of a simple pendulum?

anonymous · Answer

YES

theeric · Answer

Then you'll want the equation that uses math to describe the relationships between different physical quantities. I think I've show it to you before. I found it at http://hyperphysics.phy-astr.gsu.edu/hbase/pend.html It is:$$T=2\pi\sqrt{\frac{L}{g}}$$ $T$ is the period. $L$ is the length of the chord. $g$ is the acceleration caused by gravity. You want to solve for $L$.

anonymous · Answer

OKAY HOLD ON

anonymous · Answer

I GOT O.67 IS THAT RIGHT

theeric · Answer

It's not what I got! How did you solve for $L$?

anonymous · Answer

I squared 2 then i divided 2.0 by 9.8

theeric · Answer

I'm confused... Can you show me what you got?
You squared the 2?

anonymous · Answer

now im confused cause your confused

theeric · Answer

Haha, you start with $$T=2\pi\sqrt{\frac{L}{g}}$$Now, what did you square?

anonymous · Answer

owwww okay i see what i did wrong i was suppost to pi the 2 instead of square

theeric · Answer

Hmmm?

theeric · Answer

I would divide the equation by $2\pi$, square the equation, and multiply the equation by $g$, if you know what I mean. Then you have $L$ by itself after applicable cancelations, if you know what I mean.