====== Driven Mass on a Spring ======
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A spring with a mass attached is hung by a string that is wrapped over a pulley and connected to an armature rotated by a variable-speed motor. Operation of the motor will drive the spring-mass system and cause it to oscillate. If the motor is run at the mass-spring system's resonance frequency, the amplitude of the motion becomes so great that the string jumps off of the pulley. 

M1, F3

===Setup===

To set up: 
  - mount pulley on a rod clamped at the corner of the table, diagonally away from the table (this ensures that the mass won't hit the table at resonance)
  - attach one end of the string with a loose knot to the knob on the disk attached to the motor (not too tight! or the string will be winded around the knob)
  - pass string through pulley and hang tapered spring from it (narrow side up); there are different springs with different constants
  - at the free end hang a 100 - 1000 g mass, usually a 200-500 g mass works best with most springs
  - turn on motor and adjust speed until resonance is achieved (to turn on, make sure top knob is in a non-zero position and turn bottom left knob to forward or reverse, does not matter)
  - if there is no string, find more string in drawers next to 120
PIRA DCS 3A60.40