Physics
Mr. Harwood
Name: _________________________
Period: ____
Spring Force Table Lab
Purpose: The purpose of this lab is to investigate how the combination of various forces
affects the magnitude and direction of the resultant force (Net Force). This lab serves as
an investigation into graphical vector addition. Forces are vector quantities.
Materials: Slotted Force Table, Triple Spring Scale Attachment, Paper, Graph Paper,
Ruler, Protractor, Pencil.
Procedure:
1) Set up the slotted force table as depicted to the right. The paper
should be plain or graph paper.
2) Place a dot exactly in the center of the ring.
3) Draw lines along the long edges of the scales.
4) Record the forces on the paper next to the lines for each scale.
Convert to Newtons 102 g  1N  .
5) Remove the paper from apparatus.
6) Draw a line in the center of each pair of lines extending to the dot.
7) Point one of these lines toward you (see Fig. 2).
8) Draw axes through the dot using one of the forces (toward you) as a
guide (see Fig.3).
9) Measure the angles for each of the forces from the positive x axis
opening counterclockwise.
10) Reconfigure your system with another set of forces and angles and
repeat procedures 1-9 a second time.
A
B
C
Fig. 1
A=…N
B=…N
C=…N
Pre-Analysis Questions: Answer before moving on.
1. Is the force spring scale system in a state of equilibrium? How do you know this?
Fig. 2
2. Why may it be a good idea to align one of the forces along the axis?
A=…N
B=…N
C=…N
3. What was the purpose of converting into Newtons (N)?
Fig. 3
Analysis:
1) Obtain a piece of graph paper.
2) Select a scale to use for plotting the forces (vectors). A
good one would be 1N  4cm
3) Draw a pair of axes in the center of the page.
4) Draw vector A extending from the center (using
appropriate angle and scale length) (See Fig. 4 to right)
5) Draw vector B from the head of vector A (using
appropriate angle and scale length) (Hint: you will need
to redraw a small set of axes at the head of vector A to get
the right angle.) (See Fig. 5)
6) Draw a resultant vector (from the tail of A to the head of
B) (See Fig.6). Record its size and direction from the
original axes pair.
A
1N=0.5cm
Fig. 4
Analysis Questions:
1. What do you notice about the size of the resultant
compared to vector C?
B
2. What do you notice about the direction of the resultant
compared to vector C?
A
3. If vector C weren’t present, what would the system want
to do? Why? (Hint: Consider the situation.)
1N=0.5cm
Fig. 5
4. What situation does vector C provide for the system of
vectors A and B?
B
Hypothetical Questions:
1. Suppose you combined vector B and C in a similar way.
What would you expect the resultant to look like?
2. Suppose you combined vector A and C in a similar way.
What would you expect the resultant to look like?
Resultant
A
1N=0.5cm
Fig. 6
3. On the back side of your graph paper, combine all three vectors in a similar way.
What resultant do you obtain? (Hint: You will need to draw a third axes pair at the
head of vector B.)