Principle

Based on their knowledge of Experiment ME 2.7, the students
should determine the direction and magnitude of the resultant
force  Fr  which replaces the two
different forces  F1  and 
F2. Without knowledge of the trigonometric
functions, the evaluation can be performed graphically with the aid
of a force parallelogram or it can be calculated as a supplementary
problem, if the students are familiar with the trigonometric
functions.

The protractor sheet (circle with angular divisions) which is
required for the evaluation is provided as a master which can be
copied. The xerox copies should be given to the students before
they begin the experiment.