In an Atwood machine, one block has a mass of M1 = 520 g and the other has a mass of M2 = 320 g. The frictionless pulley has a radius of 4.6 cm. When released from rest, the heavier block moves down 51 cm in 1.00 s (no slippage). What is the tension T1? Find the pulley's moment of inertia.