PHYSICS-1
ADDITION OF VECTORS
Experiment 2: Addition of Vectors
QUAN NGUYEN
Phys 1401
DATE: 10/11/2017

PHYSICS-1
ADDITION OF VECTORS
EXPERIMENT-2: Addition of Vectors
OBJECTIVES
When a number of forces passing through the same point, act on an object, they may be
replaced by a single force which is called the resultant or the sum. The resultant therefore is
a single force which is similar in effect to the effect produced by the several forces acting on
the body. It is therefore a single force that replaces those forces. The objectives of this lab are
to use graphical, analytic and experimental methods to:
1. Resolve a force vector into its rectangular components, and
2. To find the resultant of a number of forces acting on a body.
APPARATUS
1. Force table
5. Strings for suspending the masses
2. Four weight holders
6. A ring
3. Four pulleys
7. A metal pin
4. Slotted weights
8. A protractor
9. A compass
10. Sheets of plain or graph paper.
THEORY OF VECTOR ADDITION
A.
Graphical Methods
Parallelogram Method
Vectors are represented graphically by arrows. The length of a vector arrow (drawn to scale
on graph paper) is proportional to the magnitude of the vector, and the arrow points in the
direction of the vector. The length scale is arbitrary and usually selected for convenience and
so that the vector graph fits nicely on the graph paper. See Fig 1a, where
R
=
A
+
B
. The
magnitude
R
of the resultant vector is proportional to the length of the diagonal arrow and
the direction of the resultant vector is that of the diagonal arrow
R
. The direction of
R
may be
specified as being at an angle θ relative to
A
.
Triangle Method
An equivalent method of finding
R
is to place the vectors to be added "head to tail" (head of
A
to tail of
B
, Fig. l b). Vector arrows may be moved as long as they remain pointed in the
same direction. The length and direction of the resultant is measured from the graph.
Figure 1 a: Parallelogram method
Figure 1 b: Triangle method
R
A
B
B
A
R