1 / 14

Understanding Energy: Work, Power, and Conservation Principles

Learn about the fundamental concepts of energy, work, and power, including mechanical energy, potential and kinetic energy, and the conservation of energy principles explained in a clear and concise manner.

lyneth
Download Presentation

Understanding Energy: Work, Power, and Conservation Principles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 7 Energy

  2. Introduction • Universe is made up of matter and energy. • Energy is the mover of matter. • It has several forms. To understand this concept we will begin with a closely related physical concept.

  3. 1. WORK • Work = Force x distance or W = F.d • Units - Joules (J) • Pushing on a wall and wall doesn’t move (no work done on the wall)

  4. x

  5. 2. POWER Power = Work/time or P = W/t Units - J/s = W 1 hp 1 hp = 746 J/s = 746 W 100 W bulb = 0.1341 hp 250 hp engine = 186,450 W

  6. 3. MECHANICAL ENERGY • When work is done on an object, the object generally has acquired the ability to do work. • This is called energy and it has the same units as work. Two Types of Mechanical Energy Potential Energy Kinetic Energy

  7. Potential Energy • Energy of position or configuration • Dart gun – Balestra Other examples - Springs, bow, sling shot, chemical energy, and gravitational potential energy • The latter is E = mgh

  8. The potential energy of an object depends on a reference position. • It represents the work done against gravity to put the mass m in its position h above some reference position. • It is an energy of position.

  9. Kinetic Energy • It is an energy of motion. • It is a square law. • Total Work (work done by all forces acting on mass m) = DKE

  10. Note Work to Stop KE 0

  11. Work-Energy Theorem The net work done on an object is equal to the change in the kinetic energy of the object. Net Work = DEk

  12. 4. CONSERVATION OF ENERGY • Energy is always conserved • Energy lost due to friction is actually not a loss; it is just a conversion.

  13. Energy cannot be created or destroyed. • It may be transformed from one form into another, but the total amount of energy never changes. • Energy Conservation in Satellite Motion (Next slide)

  14. Perigees Hyperbola Parabola Circle Ellipse Ellipse Energy is conserved along all of these paths. Apogees

More Related