Disposable patterns are made of

In finish machining of an island on a casting with $$CNC$$ milling machine, an end mill with $$10$$ $$mm$$ diameter is employed. The corner points of the island are represented by $$(0,0), (0,30), (50,30)$$ and $$(50,0)$$. By applying cutter radius right compensation, the trajectory of the cutter will be

A 1.5 kW motor is running at 1440 rev/min. Its is to be connected to a stirrer running at 36 rev/min. The gearing arrangement suitable for this application is

As shown in Figure, a mass of 100 kg is held between two springs. The natural frequency of vibration of the system, in cycles/s, is