Read please example 2 of http://cnx.org/content/m14060/latest/ . P1 P2 On picture 2 there are those two tension labeled by T which are equal. Why equal? And shouldn't they exert just torque? I know we are considering the pulley to be massless, so no torques. So is it correct to consider those two tensions applied at the center of mass of the pulley? Thanks in advance for your clarification.