1. The problem statement, all variables and given/known data A metronome is a device used by musicians to help them adjust the timing of their music to a standard number of beats per minute. The position of the moveable slider determines the frequency. It is possible to build a simple mechanical metronome using a light stick and two masses, as shown in the diagram. (a) Assume the metronome is displaced from the vertical by an angle, theta, as shown in the figure. Find an expression for the net torque on the metronome about the pivot. Go through the necessary steps to show that it will oscillate in SHM providing is a small angle and M1L1 > M2L2. Find an expression for the number of beats per second of the metronome (note that there are 2 beats per cycle of oscillation). (b) Suppose M1 = 0.200 kg, M2 = 0.0500 kg, and L1 = 5.0 cm. Calculate the number of beats per minute if: (i) L2 = 16.3 cm. (Check your answer: 60 beats per minute.) (ii) L2 = 6.8 cm. Here is the image for the problem question I am having: http://i43.tinypic.com/sgiwb5.png 2. Relevant equations 3. The attempt at a solution Really need help with this: The torque on M1 is –(M1 *g * L1 *sin(theta)) correct???? The torque on M2 is positive (CCW). I add them together to get net torque right? How do I add them together? Also after that, how do I find an expression for the numbe of beats per second, as stated in the question.