For you physics smarties...

Test Preparation
1

<p>Okay so this seems pretty simple </p>

<p>for the first part of the lab we drop a pendulum @ 30 deg , w/ a 30 cm radius using masses of 20 g 40g, 60, 80 etc... and measure how long it takes to go back and forth 10 times.
The period does not change due to mass because of the equation : gh=.5v^2, mass is not a factor
Is this correct reasoning? </p>

<p>but for the second part we try it using only the 20 g mass, but change the string length from 15, to 20 , to 25, to 30 cm....
the period goes DOWN as string length goes down.
What is the explanation/reasoning for this.
I put that Cent. Accel = V^2/r and since r goes down Accel is greater so the period is shorter. HOWEVER we are also changing the h in gh=.5v^2 so that as radius goes down there is less potential energy and thus less velocity?</p>

<p>i am sorta confused... can some one help me out with the reason that the period changes... i kinda feel like the experiment is badly designed but i'm not sure</p>

2

<p>no homework help allowed at CC</p>

3

<p>Your experiment is based on the equation for the period of a simple pendulum. This</a> equation is derived from the equation for the</a> period of an object in Simple Harmonic Motion. Hope that helps</p>

4

<p>It's been two years since I took physics II in high school; I've forgotten many formulas.
From what height is the pendulum dropped? You just provide the lenght of the cord.</p>

5

<p>Sorry, I don't remember stuff well enough to help. Just wanted to say to Deference though, while this is homework I think it is relevant since it would help in preparation for physics SATII and AP exam.</p>

6

<p>The rule about HW (as I understand it) is that homework help is allowed, but posting all your homework and asking for "help" on it isn't</p>