Meter Stick Lab

To better our understanding of center of gravity and torque,  we undertook "The meter stick challenge".  This involved finding the mass of a meter stick using only a meter stick, a table, and a 100g lead weight.  This certainly was a challenge, but below are the steps we took to get the mass of the meter stick.

Step I- Demo

The Demo helped with my understanding greatly. We saw the center of gravity in action, and experimented with the stick on the table.

Step II- Plan

Initially, I had little to no idea of what to do to find the meter stick's mass.  However, we did formulate a plan that got the ball rolling.  Although it is not as in-depth as other plans, it set us on the right track and we found our way.

"First, we will find the center of gravity on the meter stick by placing it hanging off of the table and seeing how far off the table it can go before falling off.  Then we will find the torques based on (force)x(lever arm)."

Step III- Try out your plan

First and foremost, we took measurements.  We found the following to be true:

-center of gravity: 50 cm

-counterclockwise lever arm: 24.8

-clockwise lever arm: 75.2 

We then took the following steps:

****To get the forces shown above, we took the following steps****

Lastly, we converted the Newtons to Kilograms and Kilograms to grams.

Tada! We found the mass of a meter stick using only a table, a weight, and a meter stick!

Center of Gravity 



Although I could have done without the excessive Coldplay, this video helped to illustrate important details of the Center of Gravity.  I found the coke can example especially helpful, and the difference between the water's and the ice's effect on the can.  I was also interested in the dollar bill/coin explanation helpful, as it showed the transition of the balance of the coin.

Angular Momentum


Silly in concept, this simple video actually helped a lot with my understanding.  It was great to actually see the change in speed as one of the students got closer to the axis of rotation.  Hopefully this video will provide an image whenever I think of Angular Momentum.