The actuator shown in Fig. 3.36 is used to raise a mass m through a dis- tance y. The coil has 500 turns and can carry a current of 20 A without overheating. The magnetic material can support a flux density of 1.5 T with negligible field intensity. Fringing may be ignored. (a) Determine the maximum air gap y for which a flux density of 1.5 T can be established with a current of 20 A. (b) What is the force exerted by the actuator for the condition of (a)? (c) The mass density of the core material is 7800 kg/m³. Determine the approximate value of the net mass that can be lifted against the force of gravity by the actuator at the air gap determined in (a). T 40 -40- 80- 240 4040 y Figure 3.36 Actuator for Problem 3.21 (all dimensions in millimeters).