For procedures, see your mechanical laboratory manual.

Title: Simple Wheel & Axle Experiment


Aim

1. To determine the velocity ratio of the machine.
2. To obtain an equation for the relationship between load and effort and hence obtain a value for the limiting efficiency of the machine.

Theory

The Simple Wheel and Axle involves two circular objects — a larger disc and a smaller cylinder, both joined at the center. The larger disc is called the wheel, and the smaller cylindrical object or rod is referred to as the axle. Sometimes, there may be two wheels attached to both ends of the axle.

A hinge or bearing supports the axle, allowing rotation. It can amplify force; a small force applied to the periphery of the large wheel can move a larger load attached to the axle.

The wheel and axle can be viewed as a version of the lever, with a driving force applied tangentially to the perimeter of the wheel and a load force applied to the axle, respectively, that are balanced around the hinge which is the fulcrum. The mechanical advantage of the wheel and axle is the ratio of the distances from the fulcrum to the applied loads, or what is the same thing the ratio of the diameter of the wheel and axle.

We know that the distance moved by the effort in one revolution the effort wheel = πD & distance moved by the load in one revolution = πd

V.R. = Distance moved by effort/ Distance moved by load = πD/ πd = D/ d

Now, M.A. = Load lifted / Effort applied = W/P and Efficiency = M.A. / V.R.

Applications

1. Revolving doors
2. Electric fans
3. Bicycle
4. Cars

References

1. Wheel and Axle, wikipedia.org
2. Examples of Wheel & Axle Simple Machines, www.sciencing.com
3. Simple Machines, wikipedia.org