Mass of Meter Stick Challenge 

The challenge was to find the mass of a meter stick only using a table, a 100g weight, and the meter stick itself. 

The first step was to get the meter stick to balance on the edge of the table while the 100g weight was on one end  This looked something like the image below. 

To balance the stick we had to create a clock-wise torque that was equal to the counter clock-wise torque. Because torque = force x lever arm    we had to find the force of the end of the stick with the weight.   

Because we know that weight = mass x gravity we plugged that in to get the equation

                                                         weight = 100 x 9.8  =  980

 And at this time the length of the lever arm was 30 cm on the left side, and was 20 cm on the right because it extended to the center of gravity on the meter stick.  
Now that we have this we can plug in our equation:
                                                          980 x 30 = X  x  20
After solving this equation we discover that the meter stick has a mass of 1470 and we then convert this into grams by simply moving the decimal point to the left. this leaves us with 147 grams.