Figure P9.74 shows a 100 g puck revolving at 100 rpm on a 20-cm-radius circle on a frict...

Figure P9.74 shows a 100 g puck revolving at 100 rpm on a 20-cm-radius circle on a frictionless table. A string attached to the puck passes through a hole in the middle of the table. The end of the string below the table is then slowly pulled down until the puck is revolving in a 10-cm-radius circle. How many revolutions per minute does the puck make at this new radius?