a) At the bottom is a 3 step pulley; consisting ofthree wheelsof different diameters.b) The rotating arm has two massesattached,and is screwed into the 3 step pulley. Whenthe pulleyrotates, so does the rod.c) The string is wrapped around one ofthewheels in the 3 step pulley and passes overthe smart pulley. Themass hanger is hooked into the loop at the end of the string.d)When the system is released, the mass hanger falls, turning thesmart pulley, and the 3 step pulley withthe rod attached. e)Assume: that the smart pulley is very light, so its moment ofinertia is negligible as compared to the moment of inertia of the 3step pulley and rod.
a)when you drop the mass holder, the system rotates at angularacceleration α. If you wrapped thestring around a larger diameter pulley and dropped the mass holder,the acceleration of the system would be:
exactlyα? less than a? more than a?
Suppose that you measured themoment of inertia of the system as I = 5.05 kg-m2. Assume the diameterof the pulley around which you wrap the string is d =2.5 cm.
a) In trial 1:the system is initially spinning at angular speedÏo = 9.27 rad/s. After you drop a disk of mass856 g on it, the system rotatesat Ïf = 8.35 rad/s. Find: - the moment of inertia of thedisk: kg-m2 - the radius of the disk: cm
b) In trial 3: suppose the system is initially spinning at angularspeed Ïo = 2.05 rad/s. After you drop a cube of mass786 g on it, the system rotatesat Ïf = 1.79 rad/s. Find: - the moment of inertia of thecube: kg-m2 - the length of one side of the cube: cm
