30. Projection Force Table

This device operates on a view graph for the whole class to see easily. Angles are measured by the circular protractor; magnitudes of the forces by the extension of the springs via Hooke's Law.

Label the rings one through seven, starting with the first black ring beyond the last red ring. The force in grams weight as measured to the base of the cone forming the vector arrow is:



1 -
2 50 gms
3 85
4 120
5 155
6 190
7 225

Force in gms. wt. = 35 X ring # - 20