9. Now you will have to use some sound judgement, as each experiment will be slightly different for each student. You should place some mass that is roughly 10%-20% of the mass of the stick, on the zero end of your ruler/meter stick. There is no need to be terribly precise in how much mass you add, just try to estimate the added mass given your answer in #5. You should attach the mass so that the masses do not fall off, by using some tape. These masses could be a few paperclips for a small ruler, or a few pens or pencils for a larger meter stick. Now balance the stick on your finger as you did in #4, only now you will likely have one difference, the position of the finger! Take a photo or make a sketch of the balanced stick and notate the position of your finger in the space below. 10. From your photo or sketch, draw a force diagram including distances to the forces from your finger. 11. Estimate how far the center of mass of the ruler or meter stick is from your finger. Write out this distance below. 12. Using Newton's Second Law of Rotational Motion, write out the equation for the diagram in #10. Note that you can place actual numbers in for the weight of the ruler or meter stick and the distance from the pivoting finger. Lastly, you know that the position of the added mass is on the end of the stick. Using these values, solve for the mass you added on the end of the stick. 13. Using your kitchen scale, a grocery scale, or google, estimate the mass of the objects you used and compare this to the calculated mass in #12