1 / 11

Energy

Ms. Moore 10/1/12. Energy. What is energy?. Energy is required for any change that occurs, no matter how small. Energy is the ability to cause change. Examples: Forms of energy: Electrical Chemical Radiant Thermal Energy can be stored and move from place to place. Kinetic Energy.

lalasa
Télécharger la présentation

Energy

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. Ms. Moore 10/1/12 Energy

  2. What is energy? • Energy is required for any change that occurs, no matter how small. • Energy is the ability to cause change. • Examples: • Forms of energy: • Electrical • Chemical • Radiant • Thermal • Energy can be stored and move from place to place.

  3. Kinetic Energy • Kinetic energy (KE) is the energy a moving object has because of its motion. • The kinetic energy of a moving object depends on an object’s mass and its speed. Kinetic energy (joules) = ½ mass (kg) x speed2 (m/s)

  4. Practice Problems • A baseball with a mass of 0.15kg is moving at a speed of 40m/s. What is the baseball’s kinetic energy? • A sprinter has a mass of 80kg and a kinetic energy of 4,000 J. What is the sprinter’s speed? • A car with a mass of 1,500kg doubles its speed from 50km/h to 100km/h. By how many times does the kinetic energy of the car increase?

  5. Lab • Read the mini lab found on page 103. • Create a table of your results and be ready for a discussion. • How did the take off speed of the nickel depend on the distance that you stretched the rubber band? • How did the KE of the nickel depend on the distance the rubber band was stretched?

  6. Potential Energy • Energy doesn’t have to involve motion. Motionless objects have energy. • Potential energy (PE) is stored energy due to position. • Examples:

  7. 3 Types of PE: • Elastic potential energy is energy stored by something that can stretch or compress • Rubber band or spring • Chemical Potential Energy is energy stored in chemical bonds • Food and gasoline

  8. Gravitational Potential Energy (GPE) is energy stored by objects due to the position above Earth’s surface. • Depends on the objects mass and height above the ground. GPE (j) = mass (kg) X 9.8 (m/s2) X height (m)

  9. Practice Problems • Find the GPE of a coffee mug with a mass of 0.3kg that is on a counter top 1m high above the ground. • How high above the ground is a baseball with a mass of 0.15kg that has a GPE of 73.5J? • A rock climber is 200m above the ground and has a GPE of 117,600J. What is the rock climber’s mass?

  10. Lab: Bouncing Balls • Why do bouncing balls stop bouncing? • Refer to page 106 • Measure tennis ball vs. bouncy ball • Include a table of results

More Related