Goal of this Lab
The goals of this lab are:
To experimentally test the vector nature of
forces.
To show that in static equilibrium the vector
sum of forces is zero.
To practice resolving vectors into components.

The force table is a round
table with a center pin and
angle divisions marked
around its outside edge.
Background
Force table
Apparatus
Pulley
Weigth
Leveling screws

Those strings are run over pulleys at different locations around the table and various masses are hung from their ends. A ring is placed around the center pin that has strings attached to it.

Each string will exert a force on the ring that is proportional to the mass hung on it and in a direction along the line of the string. Notice that force is a vector quantity. Since it has direction as well as magnitude, it is possible for two or more non–zero forces to balance out to a zero net force: equilibrium.

Background Equilibrium.
An object either at rest or moving with a constant velocity is said to be in equilibrium
The net force acting on the object is zero
(since the acceleration is zero)
Background
Easier to work with the equation in terms of its components:
∑ Fx=0 and ∑ Fy=0

1. Apply 3 concurrent forces to the central ring, hanging a 200 g at 270° and masses of 150 g and 100 g on the other two hangers.
1. Adjust the positions of the other 2 strings until the central ring floats freely and well centered with respect to the centering pin.
1. Draw an sketch of this equilibrium force arrangement on your data book with all mass and angle data.

Procedure Part 1

Angles are to be expressed relative to a superimposed coordinate system, choosing the +X–axis to lie along the 0° direction of the force table.
4. Repeat for 200 g at 270° and masses of 200 g and 150 g.
5. Repeat for 250 g at 270° and masses of 150 g and 150 g.
6. You should have 3 different diagrams, one for each experiment, in your data book.
Procedure Part I

Procedure Part II
1. Calculate theoretically the resultant, angle and magnitude, if we hang masses of 100g, 150g and 200g at angles of 30°, 120° and 330°, respectively.
1. Add a fourth pulley to the Force Table and prove your results.