Term: 3^{rd} Term
Week: 8
Class: Senior Secondary School 1
Age: 15 years
Duration: 40 minutes of 5 periods each
Date:
Subject: Physics
Topic: Vector resolution
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures
INSTRUCTIONAL PROCEDURES
PERIOD 12
PRESENTATION 
TEACHER’S ACTIVITY 
STUDENT’S ACTIVITY 
STEP 1 INTRODUCTION 
The teacher reviews the previous lesson on vectors 
Students pay attention 
STEP 2 EXPLANATION 
He defines and explains vector resolution. He explains the methods of vector resolution

Students pay attention and participates 
STEP 3 DEMONSTRATION 
He explains the guidelines for finding the resultant of two or more vectors and carries out some calculations

Students pay attention and participate 
STEP 4 NOTE TAKING 
The teacher writes a summarized note on the board 
The students copy the note in their books 
NOTE
VECTOR RESOLUTION
The process of determining the magnitude of a vector is known as vector resolution. The two methods of vector resolution are:
Parallelogram law of vector addition states that if two vectors acting at a common point are represented in magnitude and direction by the adjacent sides of a parallelogram, their resultant is represented in magnitude and direction by the diagonal of the parallelogram drawn from their common point of intersection and direct away from that point.
Example: Two forces with magnitudes of 25N and 18N respectively are inclined at an angle of 120^{0} to each other. Calculate the resultant force and the angle it makes with the 18N force.
R^{2} = A^{2} + B^{2} – 2ABcos(180^{0}ϴ)
R^{2} = 25^{2} + 18^{2} – 2 x 25 x 18cos(180^{0}120^{0})
R^{2} = 625 + 324 – 900cos60^{0}
R^{2} = 499
Resultant, R = 22.34N
RESULTANT OF TWO OR MORE VECTORS BY RESOLUTION
The resultant of two or more vectors can be found by taking the following simple steps:
ΣFx
Example: Three coplanar forces act simultaneously at a point as shown below
Find the resultant of the forces and its direction with respect to xaxis.
(Take sin60^{0} = 0.87, cos60^{0} = 0.50
Solution:
VERTICAL COMPONENT Ry 
HORIZONTAL COMPONENT Rx 
107 sin90^{0} 
107cos90^{0} 
100sin60^{0} 
100cos60^{0} 
80sin0^{0} 
80cos0^{0} 
ΣFy= 20N 
ΣFx = 30N 
R = √30^{2}+ 20^{2}
R = √1300
R = 36.1N
Direction is given as tanϴ = ΣFy
ΣFx
tanϴ = ΣFy
ΣFx
= 20
30
ϴ = 33.7˚
EVALUATION: 1. Define vector resolution
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively