Chapter 04: Work and Energy

This is a forth chapter of the book Physics 11 published by Punjab Curriculum and Textbook Board, Lahore, Pakistan.

After studying this chapter the students will be able to:

* Understand the concept of work in terms of the product of a force and displacement in the direction of the force.

• Understand and derive the formula Work = wd = mgh 'or work done in a gravitational field near Earth's surface.
• Understand that work can calculated from area under the force-displacement graph.
• Relate power to work done.
• Define power as the product of force and velocity.
• Quote examples of power from everyday life.
• Explain the two types of mechanical energy.
• Understand the work-energy principle.
• Derive an expression for absolute potential energy.
• Define escape velocity.
• Understand that in a resistive medium loss of potential energy of a body is equal to gain in kinetic energy of tho body plus work done by the body against friction.
• Give examples of conservation of energies from everyday life.
• Describe some non-conventional sources of energy.