posted by monica on .
an air puck of mass 0.347 kg is tied to a string and allowed to revolve in a circle of radius 1.09 m on a horizontal, frictionless table. The other end of the string passes through a hole in the center of the table and a mass of 1.48 kg is tied to it. The suspended mass remains in equilibrium while the puck revolves. What is the tension in the string?
Since the string tension supports the 1.48 kg mass that dangles from it, in equilibrium,
T = M g = 14.50 N
You don't need the information on the air puck on the table to compute the tension, but you could use the tension to compute the required speed of the air puck.
Kind of a trick question. You have to know what information to use and what to ignore. Just like life.