The apparatus consists of the arm, hanger with loads, spring balance and protractor scale attached to the support board. The apparatus mainly focuses on the fact that work done by a variable force can be determined by measuring the area under the graph of force and distance travelled.
One end of the arm is fixed and its position is indicated by the protractor. Other end of arm carries the load hanger, and is restrained by spring balance that is perpendicular to the arm. The spring balance is also fixed with a nail. Under the application of load, the movement of arm can be read easily.