Work, Energy, and Momentum - Physics (Undergraduate Foundation)

This course provides an alternative, and often more efficient, approach to solving mechanics problems using the principles of work, energy, and momentum. It develops the work-energy theorem and the foundational laws of conservation of energy and conservation of linear momentum. These scalar (energy) and vector (momentum) methods are critical for analysing complex systems. The conservation laws are among the most fundamental and powerful principles in all of science. They are applied in every field, from analysing planetary motion and particle collisions to understanding chemical reactions and engineering efficient machines. This course provides the mechanical foundation for these universal laws. By the end of this course, you will be able to calculate the work done by a constant or variable force, apply the work-energy theorem to relate work and kinetic energy, solve problems using the principle of conservation of mechanical energy involving kinetic and potential energy, and apply the law of conservation of linear momentum to analyse collisions. This course is a core requirement for all first-year university students of physics and engineering. It builds directly upon Newtonian dynamics and is the essential prerequisite for studying thermodynamics, fluid mechanics, and modern physics.

Enrolment valid for 12 months

This course is also part of the following learning track. You may join the track to gain comprehensive knowledge across related courses.

PHY 101: General Physics I - Mechanics

This learning track provides a complete and rigorous treatment of introductory classical mechanics as specified by the NUC Core Curriculum. It is structured to build a comprehensive analytical framework, starting with the mathematical description of motion (kinematics) and progressing through its causes (Newtonian dynamics), the powerful conservation laws, the dynamics of rotating systems, and finally, the principles of universal gravitation. Mastery of this material is the non-negotiable foundation for all subsequent study in physics and engineering. The principles of classical mechanics are the operational language for analysing the physical world. This track provides the essential toolset for solving problems in every field of engineering, from aerospace to civil, and for understanding phenomena from the trajectory of a projectile to the orbits of planets. By the end of this track, you will be able to analyse motion using vectors and calculus, apply Newton's laws to solve any standard dynamics problem, use conservation laws to analyse complex systems and collisions, analyse rotational motion, and solve problems in celestial mechanics. This learning track is a mandatory prerequisite for all first-year university students of physics, engineering, and related physical sciences. It provides the foundational knowledge required for all subsequent courses in mechanics, electromagnetism, thermodynamics, and modern physics.

Course Chapters

1. Introduction

This chapter introduces the concepts of work and energy. It establishes them as a powerful alternative framework to Newtonian dynamics for analysing motion, particularly when forces are not constant. Key objectives include understanding the course structure and the fundamental definitions of work, energy, and the conservation laws that govern them.

Concept Overviews

1 Lesson

2. Work and Kinetic Energy

This chapter provides a formal definition of mechanical work and kinetic energy. It culminates in the work-energy theorem, a fundamental principle that directly relates the work done on an object to the change in its kinetic energy. Key topics include the definition of work done by a constant force, the definition of kinetic energy, and the statement and application of the work-energy theorem.

Concept Overviews

3 Lessons

Problem Walkthroughs

4 Lessons

3. Potential Energy and Conservation of Energy

This chapter introduces potential energy and the law of conservation of mechanical energy. This is one of the most fundamental principles in physics, providing a powerful method for solving problems where only conservative forces are involved. Key topics include gravitational and elastic potential energy, the definition of conservative forces, and the application of the conservation of mechanical energy principle.

Concept Overviews

3 Lessons

Problem Walkthroughs

4 Lessons

4. Linear Momentum and Collisions

This chapter covers the principle of conservation of linear momentum. This law is essential for analysing collisions and explosions, particularly in systems where the forces are complex or unknown. Key topics include the formal definition of linear momentum, the impulse-momentum theorem, and the application of momentum conservation to solve problems involving elastic and inelastic collisions.

Concept Overviews

3 Lessons

Problem Walkthroughs

4 Lessons

5. Centre of Mass

This chapter introduces the concept of the centre of mass. It provides a method for simplifying the analysis of complex, extended objects or systems of particles by treating them as a single point mass. Key topics include the definition and calculation of the centre of mass for discrete and continuous systems, and the principle that the centre of mass moves as if all external forces were applied to it.

Concept Overviews

2 Lessons

Problem Walkthroughs

4 Lessons

6. Conclusion

This chapter consolidates the energy and momentum methods for analysing motion. It provides a structured summary of the work-energy theorem and the laws of conservation of energy and momentum, reinforcing these powerful problem-solving tools. The conclusion summarises the key principles and their conditions of use. It also provides a forward look to the next course on rotational motion, where these concepts will be extended.

Concept Overviews

2 Lessons