1 / 8

Understanding Work and Energy in Physics

Learn about the definitions of work and energy in physics and how they are calculated through various examples and equations in different scenarios. Understand the concept of energy transfer and the relationship between force, distance, and work.

beau-hull
Télécharger la présentation

Understanding Work and Energy in Physics

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. How does it do that? 3.2.1 Introduction to Work & Energy

  2. Definitions • energy: ABILITY TO DO WORK • Unit: JOULE • work: A CHANGE IN TOTAL ENERGY • requires MOTION • Unit: JOULE Equation

  3. Example #1 – No Motion • A student is trying to push a heavy crate across the floor, but it does not move. • Is work being done ‘on the crate’? No, work is NOT being done ‘on the object’ unless it moves.

  4. Example #1 – No Motion • But it feels to the student like energy is being used -- what’s going on? Energy IS being expended and work IS being done, just not ‘on the object’. Work is being done inside the student’s body.

  5. Example #2 – Flat Ground • A box is pushed with a force of 100 newtons across a frictionless surface for a distance of 10 meters. • How much work is done on the box? W = Fd = ΔET W = (100N)(10m) W = 1000 J 100 N 10 m

  6. Example #3 – Incline • A box is pulled up a 3.0 meter long plane that is inclined at 20° using a force of 10 newtons. • How much work is done in moving the box? W = Fd = ΔET W = (10N)(3.0m) W = 30 J 10 N 3.0 m 20°

  7. Example #4 – Force on an Angle • A sled is pulled a horizontal distance of 4.0 meters across a frictionless surface using a force of 15 newtons at an angle of 30° above the horizontal. • How much work is done on the sled? W = Fd cos θ =ΔET W = (15N)(4.0m) cos(30°) W = 52 J 15 N 30° 4.0 m

  8. End of 3.2.1 - PRACTICE

More Related