Task: To determine the mechanical efficiency of screw driver.
Required accessories: Two screw drivers of different size, two screw of the same length, soft wood.
Procedure: At first one of the student drive a screw with a small screw driver. In this case he will rotate the handle for five complete cycles. Similarly see by rotating the long handled screw driver 5 for five cycles. Have any differences been noticed? These differences will tell you what type of screw driver you should use to avail the mechanical efficiency of a screw driver.
In the case of a screw, the mechanical advantage is the ratio of the circumference of the screw to the distance traveled after each revolution. In other words, IMA = 2*pi*L / P, where L is the radius of the screw and P is the distance traveled after each revolution.