Force & Motion

79,351 views

Published on

intro to force & motion 9th grade level

Published in: Technology
4 Comments
112 Likes
Statistics
Notes
  • Thanks for sharing.......... file is wonderful
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • This file is wonderful! THANK YOU!
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • ya lor
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • The thing sucks the most, You tube is way better!!!!!!!!!!!!!!!!!!!!
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
No Downloads
Views
Total views
79,351
On SlideShare
0
From Embeds
0
Number of Embeds
1,006
Actions
Shares
0
Downloads
6,905
Comments
4
Likes
112
Embeds 0
No embeds

No notes for slide

Force & Motion

  1. 1. Motion & Forces
  2. 2. Speed & Velocity <ul><li>Speed - the rate of change in position over time (distance/time) </li></ul><ul><li>Instantaneous speed </li></ul><ul><li>Average speed </li></ul><ul><li>How is velocity different from speed? </li></ul>Velocity describes both speed and direction
  3. 3. Change in Velocity <ul><li>What makes an object change velocity? </li></ul>
  4. 4. Force <ul><li>Push or Pull </li></ul><ul><li>Forces can cause a change in velocity </li></ul><ul><li>Examples: </li></ul>Gravity Magnetism Friction
  5. 5. Balanced Forces <ul><li>Forces that </li></ul><ul><ul><li>act on the same object </li></ul></ul><ul><ul><li>are opposite in direction </li></ul></ul><ul><ul><li>are equal in size </li></ul></ul>
  6. 6. Balanced Forces <ul><li>Book on table </li></ul><ul><ul><li>Weight of the book is downward force caused by gravity </li></ul></ul><ul><ul><li>Table pushes back with an equal and opposite force </li></ul></ul><ul><li>Net force is zero </li></ul>
  7. 7. Unbalanced Forces <ul><li>Forces that are NOT opposite and equal </li></ul><ul><li>What do they cause? </li></ul><ul><li>CHANGE IN VELOCITY </li></ul><ul><li>ACCELERATION </li></ul>
  8. 8. Friction <ul><li>Force that opposes motion between 2 surfaces </li></ul><ul><li>Depends on the: </li></ul><ul><ul><ul><li>types of surfaces </li></ul></ul></ul><ul><ul><ul><li>force between the surfaces </li></ul></ul></ul>
  9. 9. Types of Friction <ul><li>Static Friction: (Couch Potato) </li></ul><ul><ul><li>Force between objects at rest </li></ul></ul><ul><li>Sliding Friction: (Ice skating) </li></ul><ul><ul><li>Solid surfaces slide over each other </li></ul></ul><ul><li>Rolling Friction: (Rollerblading) </li></ul><ul><ul><li>An object rolls over a surface . </li></ul></ul><ul><li>Fluid friction: (Submarine) </li></ul><ul><ul><li>An object moves through a fluid </li></ul></ul>
  10. 10. Friction <ul><li>Friction is greater... </li></ul><ul><ul><li>between rough surfaces </li></ul></ul><ul><ul><li>when there’s greater force between surfaces (such as more weight) </li></ul></ul>
  11. 11. Lubricant <ul><li>Changes sliding friction into fluid friction </li></ul>
  12. 12. Friction <ul><li>Is friction always bad? </li></ul>
  13. 13. Gravity <ul><li>The attractive force between all objects in the universe </li></ul>
  14. 14. Acceleration of Gravity <ul><li>Near the surface of the earth the acceleration due to gravity is 9.8 m/s/s </li></ul>
  15. 15. Newton’s 1 st Law <ul><li>An object at rest remains at rest and an object in motion will continue moving at a constant velocity unless acted on by unbalanced forces. </li></ul>
  16. 16. Newton’s Laws of Motion
  17. 17. Newton’s 1 st Law <ul><li>INERTIA </li></ul><ul><li>tendency of an object to resist any change in its motion </li></ul><ul><li>increases as mass increases </li></ul>
  18. 18. Newton‘s 2 nd Law <ul><li>If more force is applied, an object will be accelerated _____ </li></ul>more
  19. 19. Newton’s 2 nd Law <ul><li>More force means more acceleration </li></ul><ul><li>More mass means less acceleration </li></ul><ul><li>Force = mass X acceleration </li></ul>F = ma
  20. 20. Newton’s 3 rd Law <ul><li>For every action, there is an equal and opposite reaction. </li></ul><ul><li>Forces occur only in pairs </li></ul><ul><ul><li>Act on different objects </li></ul></ul><ul><ul><li>Equal and opposite </li></ul></ul>
  21. 21. Newton’s 3 rd Law <ul><li>The hammer exerts a force on the nail to the right. </li></ul><ul><li>The nail exerts an equal but opposite force on the hammer to the left. </li></ul>
  22. 22. Momentum
  23. 23. Terminal Velocity <ul><li>The final speed of a falling object. </li></ul>
  24. 24. Terminal Velocity <ul><li>Air resistance is offsetting the the weight of the object </li></ul>
  25. 26. Forces End
  26. 27. Force <ul><li>Aristotle's idea: </li></ul><ul><li>For an object to move at a constant speed, a constant force must be applied. </li></ul>
  27. 28. Force <ul><li>Newton’s idea: </li></ul><ul><li>An object moving at a constant speed will continue at that speed without additional force being applied. </li></ul>
  28. 29. Balanced Forces

×