Final answer:
The free body diagram of the mass m in a conical pendulum is a conical shape.
Step-by-step explanation:
The free body diagram of the mass m in a conical pendulum would look like a conical shape. The weight of the bob acts downward, while the tension in the string acts inward towards the center of the circle. The resultant of these two forces provides the necessary centripetal force to keep the bob moving in a horizontal circle.