1. The problem statement, all variables and given/known data A puck, mass m, on the end of a (thin, light) string rotates in a circle of radius r_0 at a speed v_0 on a frictionless table. The radius of the circle is slowly reduced from its initial value by pulling the string through a hole in the table. A. Hence write down an expression for the speed of the mass when the radius is reduced to some radius r B. Write down an expression for the tension in the string and show it goes like 1/r^3 2. Relevant equations v=rw 3. The attempt at a solution i split the above problem into two systems. rotational and kinematic. the kinetic energy is 0.5mrw^2-0.5^mr_0w^2. For the rotational system i am unsure how this is linked to tension ?. Is my starting point correct ?.