A type of level indicator incorporates four hemispherical cups with open fronts mounted as shown in Fig.

Question:

A type of level indicator incorporates four hemispherical cups with open fronts mounted as shown in Fig. 17.13. Each cup is 25 mm in diameter. A motor drives the cups at a constant rotational speed. Calculate the torque that the motor must produce to maintain the motion at 20 rpm when the cups are in

(a) Air at 30°C

(b) Gasoline at 20°C.

Motor Direction of rotation 75 mm typ.