A.Y 2018-2019
PHYSICS I
LABORATORY
ACTIVITY #
INDIVIDUAL REPORT
SUBMITTED BY:
EUNNICE E. PANALIGAN
SUBMITTED TO:
ENGR. RAFAEL DIMACULANGAN
I.
II.
III.
OBJECTIVE
At the end of the activity, you should be able:
a) To determine the magnitude and direction of the equilibrant and resultant
vector using the force table.
b) To determine the magnitude and direction of the resultant vector using the
polygon method (graphical method)
MATERIALS
1
Force table apparatus
1
Set of weights
1
m String
1
Protractor
1
Ruler
DATA AND RESULTS
TABLE 2.1 Force Table (Experimental Values)
VECTOR
MAGNITUDE
A
B
C
Equilibrant (E)
Resultant (R)
TABLE 2.2 Summary of Results
RESULTANT
MAGNITUDE (N)
Polygon Method
Component Method
% Difference
DIRECTION
DIRECTION (degrees)
IV.
EXPERIMENT DISCUSSION
A scalar quantity is a number that has only a magnitude. When scalar
quantities are added together (e.g., prices), the result is a sum. Vectors are
quantities that have both magnitude and direction; specific methods of addition are
required. When vector quantities are added, the result is a resultant.
There are several ways on how to add vectors like the Tail-To-Head Method
and the Component Method. A vector can be moved to any location; so long as its
magnitude and orientation are not changed, it remains the same vector. When
adding vectors, the order in which the vectors are added does not change the
resultant. It can be achieved by Drawing each vector on a coordinate system;
beginning each from the origin. Next is choose any vector drawn to be the first
vector. Then choose a second vector and redraw it, beginning from the end of the
first. Repeat, by adding as many vectors as are desired to the end of the “train” of
vectors. The resultant is a vector that begins at the origin and ends at the tip of the
last vector drawn. It is the shortest distance between the beginning and the end of
the path created.
For the Component Method, it is used to add vectors by components,
calculate how far each vector extends in each dimension. The lengths of the x- and ycomponents of a vector depend on the length of the vector and the sine or cosine of
its direction.
After getting the results from polygon method and component method, we
will now use the force table to verify our results of vector addition and gain a handson perspective. The force table is a circular steel disc with angles 0 to 360 inscribed
on the edge. As noted above, when adding vectors, a resultant vector is determined.
To balance the force table, however, a force that is equal in magnitude but opposite
in direction must be used. This force is the equilibrant,
V.
GUIDE QUESTIONS
1. Two forces, one of magnitude 2N and the other one of magnitude 3N, are applied
to the ring of the force table. The direction of the two forces are unknown.
Which of the following best describes the limitation on the resultant, R? Explain
the basis of your answer?
2. Using the set of vectors in this exercise, compute the resultant vector R = A + B +
C using the component method. Show the detailed solution.
VI.
CONCLUSION
A variety of mathematical operations can be performed with and upon vectors.
One such operation is the addition of vectors. Two vectors can be added together to
determine the result (or resultant). There are a variety of methods for determining
the magnitude and direction of the result of adding two or more vectors. The two
methods that will be discussed in this lesson and used throughout the entire unit
are:
o The Pythagorean Theorem and Trigonometric methods
o The head-to-tail method using a scaled vector diagram
By using the Pythagorean Theorem and Trigonometric Method it is best to use
when finding the resultant vector. Meanwhile in head-to-tail method, involves drawing a
vector to scale on a sheet of paper beginning at a designated starting position. Where the
head of this first vector ends, the tail of the second vector begins (thus, head-totail method). The process is repeated for all vectors that are being added. Once all the
vectors have been added head-to-tail, the resultant is then drawn from the tail of the first
vector to the head of the last vector; i.e., from start to finish. Once the resultant is drawn, its
length can be measured and converted to real units using the given scale. The direction of
the resultant can be determined by using a protractor and measuring its counterclockwise
angle of rotation from due East.
Another thing for undermining the vector sum is by the use of the force table. A
force board (or force table) is a common physics lab apparatus that has three (or
more) chains or cables attached to a center ring. The chains or cables exert forces
upon the center ring in three different directions. Typically the experimenter adjusts
the direction of the three forces, makes measurements of the amount of force in
each direction, and determines the vector sum of three forces. Forces perpendicular
to the plane of the force board are typically ignored in the analysis.
VII.
COMPUTATION