Screw Jack

A Screw Jack consist of a cylinder with a spiral ridge runs round it. The spiral is called the thread (T) and the distance between two adjacent threads is called the pitch (p) of the screw.
Consider the following diagram.

Example 1

 A screw jack with a pitch of 0.2cm and a handle of length 50cm is used to lift a car of weight 1.2 x 10⁴N. If the efficiency of the screw is 30%, find:

a)    The velocity ratio and mechanical Advantage of the machine.  CONTINUE READING