Lesson Note on Projectiles for SS1 (SSS 1)

Class: Senior Secondary School 1 (SS1, SS 1, SSS1, SSS 1)
Term: 3rd Term
Week: 9
Age: 15 years
Duration: 45 minutes
Subject: Physics
Curriculum Theme: Physics
Previous Lesson: Mechanical Energy.
Topic: PROJECTILES
Subject Matter: Concept of projectiles, ways of projecting an object, vertical projection, horizontal projection, projection at an angle to the horizontal, range, maximum height, time of flight, solving simple problems involving range height and time of flight, demonstration of projectile motion using a thrown ball.

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

• Define projectile motion and give examples.
• Distinguish between vertical, horizontal, and angled projection.
• State the formulas for range, maximum height, and time of flight for a projectile.
• Solve simple numerical problems involving range, height, and time of flight.

Affective Domain:

• Appreciate the practical applications of projectile motion in sports and daily life.
• Show interest in observing and analyzing different types of motion.
• Develop a scientific attitude towards problem-solving in physics.

Psychomotor Domain:

• Demonstrate projectile motion using a thrown ball.
• Accurately measure and record data from a simple projectile demonstration.
• Sketch basic projectile paths.

Social Domain:

• Collaborate with peers to discuss examples of projectile motion.
• Effectively communicate solutions to numerical problems.

Reference Materials

The following resources were used in planning this lesson:

• 9 Years Basic Education Curriculum for Physics.
• State Unified Scheme of Work for Senior Secondary Schools.
• New School Physics by P.N. Okeke and M.W. Anyakoha.
• https://www.waecdirect.org/curriculum/physics/
• https://www.nairaland.com/7085731/physics-ss1-ss2-ss3-notes

Instructional Materials

The teacher will teach this lesson with the aid of:

• A ball
• An open space or wall for demonstration
• Measuring tape
• Stopwatch
• Charts illustrating projectile paths
• Worksheets with practice problems

Rationale for the Lesson

This lesson helps pupils understand how objects move when thrown or launched into the air. It enables them to apply physics principles to analyze the motion of everyday objects like a kicked ball or a javelin, making the concepts of force and gravity more relatable to their daily experiences.

Prerequisite/Previous Knowledge

Pupils should have prior knowledge of basic concepts of motion, force, gravity, and vectors.

Lesson Content/Board Summary

PROJECTILES

Concept of Projectiles

A projectile is any object that is thrown or projected into the air and is then subject only to the force of gravity. Its motion is called projectile motion. The path followed by a projectile is known as its trajectory, which is typically parabolic.

Examples of projectiles include:

• A stone kicked from the ground.
• A javelin thrown by an athlete.
• A bullet fired from a gun.
• A ball thrown into the air.

Ways of Projecting an Object

Objects can be projected in different ways, leading to distinct types of projectile motion:

• Vertical Projection: The object is thrown straight upwards or downwards. In this case, the horizontal component of velocity is zero.
• Horizontal Projection: The object is thrown horizontally from a certain height. The initial vertical velocity is zero.
• Projection at an Angle to the Horizontal: The object is thrown upwards at an angle to the horizontal. This is the most general and common type of projectile motion.

Key Terms in Projectile Motion

When an object is projected at an angle, its motion is described by several important terms:

• Range (R): This is the total horizontal distance covered by the projectile from its point of projection to the point where it lands on the same horizontal level.
• Maximum Height (H): This is the greatest vertical distance reached by the projectile from its point of projection.
• Time of Flight (T): This is the total time taken by the projectile from the moment of projection until it lands on the same horizontal level.
• Trajectory: The curved path followed by the projectile.

Solving Simple Problems on Projectile Motion

The motion of a projectile can be analyzed by resolving its initial velocity into horizontal and vertical components. The horizontal motion is uniform (constant velocity, neglecting air resistance), while the vertical motion is under constant acceleration due to gravity (g).

For a projectile launched with initial velocity ‘u’ at an angle ‘θ’ to the horizontal, the following formulas are used:

• Time of flight (T): T = (2u sinθ) / g
• Maximum height (H): H = (u² sin²θ) / (2g)
• Horizontal Range (R): R = (u² sin2θ) / g

where ‘g’ is the acceleration due to gravity (approximately 9.8 m/s² or 10 m/s²).

Simple problems involve substituting given values into these formulas to calculate the unknown quantities.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Set Induction

Teacher’s Activity: The teacher begins the lesson by throwing a ball against a vertical wall or into the air, asking pupils to observe its path. The teacher then asks questions like, “What path does the ball follow?”, “What forces are acting on the ball after it leaves my hand?”.

Pupils’ Activity: Pupils observe the thrown ball and respond to the teacher’s questions, sharing their initial thoughts on the ball’s motion and the forces involved.

Learning Point: Pupils are introduced to the concept of projectile motion through a practical demonstration and activate their prior knowledge.

Step 2: Concept of Projectiles

Time: 7 minutes

Teaching Skill: Explanation/Definition

Teacher’s Activity: The teacher formally defines a projectile and projectile motion, explaining that it is motion under gravity alone. The teacher lists and discusses various examples of projectiles from daily life and sports, writing key points on the board.

Pupils’ Activity: Pupils listen attentively, copy notes from the board, and contribute more examples of projectiles from their own experiences.

Learning Point: Pupils understand the definition of a projectile and can identify examples.

Step 3: Ways of Projecting an Object

Time: 7 minutes

Teaching Skill: Classification/Illustration

Teacher’s Activity: The teacher explains and illustrates the three main ways of projecting an object: vertical, horizontal, and at an angle to the horizontal. The teacher uses diagrams or gestures to show the initial direction of projection for each type.

Pupils’ Activity: Pupils observe the illustrations, ask clarifying questions, and take notes on the different types of projection.

Learning Point: Pupils can distinguish between different ways an object can be projected.

Step 4: Key Terms in Projectile Motion

Time: 7 minutes

Teaching Skill: Explanation/Visual Aids

Teacher’s Activity: The teacher introduces and defines the key terms associated with projectile motion, specifically when projected at an angle: Range, Maximum Height, and Time of Flight. The teacher uses charts showing projectile paths to clearly point out these quantities.

Pupils’ Activity: Pupils listen, observe the charts, and copy the definitions of the key terms into their notebooks.

Learning Point: Pupils understand the meaning of Range, Maximum Height, and Time of Flight.

Step 5: Formulas and Simple Problem Solving

Time: 8 minutes

Teaching Skill: Problem Solving/Derivation

Teacher’s Activity: The teacher writes the formulas for Time of Flight, Maximum Height, and Range on the board. The teacher then works through a simple example problem, showing how to substitute values into the formulas and calculate the unknowns, explaining each step clearly.

Pupils’ Activity: Pupils copy the formulas and the worked example, paying attention to the steps involved in solving the problem.

Learning Point: Pupils learn the formulas for projectile motion and how to apply them in simple calculations.

Step 6: Practice Problem

Time: 5 minutes

Teaching Skill: Guided Practice

Teacher’s Activity: The teacher provides a similar simple problem for pupils to solve on their own or in pairs, circulating to offer guidance and assistance where needed. The teacher then calls on a pupil to present their solution on the board.

Pupils’ Activity: Pupils attempt to solve the practice problem. A selected pupil writes their solution on the board and explains it.

Learning Point: Pupils practice applying the formulas and reinforce their problem-solving skills.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is a projectile? Give two examples.
2. Mention two ways an object can be projected.
3. Define ‘Range’ and ‘Time of Flight’ in projectile motion.
4. State the formula for calculating the maximum height of a projectile.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 1 minute

Teaching Skill: Summarization

Teacher’s Activity: The teacher briefly summarizes the key points of the lesson, emphasizing the concept of projectile motion and its applications. The teacher gives homework to solve more problems on projectile motion from the textbook.

Pupils’ Activity: Pupils listen to the summary and note down the homework assignment.

Learning Point: Pupils consolidate their learning and are encouraged to practice further.

Lesson Keywords

• Projectile – An object thrown or projected into the air, subject only to gravity.
• Trajectory – The path followed by a projectile.
• Range – The horizontal distance covered by a projectile.
• Maximum Height – The highest vertical point reached by a projectile.
• Time of Flight – The total time a projectile spends in the air.
• Vertical Projection – Object thrown straight up or down.
• Horizontal Projection – Object thrown horizontally from a height.
• Angled Projection – Object thrown at an angle to the horizontal.

Differentiation

For pupils who grasp concepts quickly, the teacher can provide more complex problems involving vector components or varying launch heights. For pupils needing more support, the teacher can provide step-by-step guides for formula application and simplified problems, or pair them with stronger pupils for collaborative learning.

Note for teachers using this lesson plan

Ensure the demonstration with the ball is clear and visible to all pupils. Emphasize the role of gravity and neglect of air resistance in ideal projectile motion. Encourage pupils to relate the concepts to real-world scenarios like sports. Using visual aids like charts or animations can greatly enhance understanding of trajectories and components of motion.