1 / 16

More Energy

More Energy. and some example problems. Quick Review. Energy is what causes work to be done Kinetic Energy KE= ½ mv 2 Potential Energy PE=mgh Conservation of Energy Δ KE=- Δ PE. Conservation of Energy if system is not closed .

allegra-lawrence
Download Presentation

More 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. More Energy and some example problems

  2. Quick Review • Energy is what causes work to be done • Kinetic Energy • KE= ½ mv2 • Potential Energy • PE=mgh • Conservation of Energy • ΔKE=-ΔPE

  3. Conservation of Energy if system is not closed • Conservation of Energy can be used to solve problem even without a closed system • The energy lost from the system goes into Work

  4. Conservation Forces have energy conserved Gravity Potential Energy ΔPE=-ΔKE Non-Conservative forces have energy turn into Work Friction ΔPE=W=Fdor ΔKE=W=Fd Conservative and non-Conservative forces

  5. Find the Kinetic Energy • A) 50 kg bowling ball with a velocity of 20 m/s • B) A 9.11x10-31 kg electron with a velocity of 3.00x107 m/s • C)A 1 kg ice block with a velocity of 1 m/s

  6. Find the Potential Energy • A) 50 kg bowling ball 20 meters high • B) A 9.11x10-31 kg electron with a height of 155 meters • C)A 1 kg ice block with a height of 5565 m

  7. Spring Potential Energy • PEelastic=½kx2 • k-spring constant • Ex: A block on a vertical spring with a k= 5.00 x 103 N/m and is pushed downward, compressing the spring 0.100 m. What is the potential energy of the spring?

  8. Conservation of Energy Ex: Problems • A) 50 kg bowling ball with a velocity of 20 m/s is thrown into the air. At what height will it stop? • B) 50 kg bowling ball is 20 meters high. What is the velocity just before it hits the ground?

  9. Ex: A block on a vertical spring with a k= 5.00 x 103 N/m and is pushed downward, compressing the spring 0.100 m. If the block has a mass of .25kg: A. What is the potential energy of the spring? • How fast is the block moving when released from the spring? • What is the maximum height reached by the block?

  10. Some energy lost to friction • A 65 kg refrigerator slides down 10. meters along a driveway against a force of friction of 12N. If the refrigerator ends .60 meters below its original starting point what is the final velocity?

More Related