1)    A lead screw and saddle arrangement is used to lift a load of 200 kg. The square thread has a pitch of 8 mm and a diameter of 30 mm. The coefficient of friction is 0.2. Calculate the torque needed to rotate the screw on raising and lowering.

2)    A screw Jack must raise a load of 500 kg. The thread has a pitch of 10 mm and a diameter of 50 mm. The coefficient of friction is 0.15. The effort is applied through a lever of radius 400 mm. Calculate the efficiency and the effort required to raise the load.

3)    Find the greatest and smallest values of the velocity ratio of two shafts joined with a universal coupling when the axis are at 38.

4)    Explain what conditions are required in order to obtain a constant velocity joint for the universal coupling mentioned in part a). A suggested word count of 150 words 10% is required for this task.

5) Select and examine two different types of mechanica