1 / 23

More 2D Motion: On a Ramp and Relative

More 2D Motion: On a Ramp and Relative More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: More 2D Motion: On a Ramp and Relative

emily
Download Presentation

More 2D Motion: On a Ramp and Relative

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 2D Motion: On a Ramp and Relative

  2. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall:

  3. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall:

  4. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: afreefall = 9.8 m/s2 (down)

  5. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: afreefall = 9.8 m/s2 (down) This is the only acceleration causing the cart to roll—if there were no gravity then the cart would stand still!

  6. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: Let’s now break afreefall into two component vectors: one parallel to the ramp and one perpendicular to the ramp. afreefall = 9.8 m/s2 (down) This is the only acceleration causing the cart to roll—if there were no gravity then the cart would stand still!

  7. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: Let’s now break afreefall into two component vectors: one parallel to the ramp and one perpendicular to the ramp. afreefall = 9.8 m/s2 (down) This is the only acceleration causing the cart to roll—if there were no gravity then the cart would stand still!

  8. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: afreefall = 9.8 m/s2 (down)

  9. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: Only the parallel [green] component causes motion along the ramp. afreefall = 9.8 m/s2 (down)

  10. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: Only the parallel [green] component causes motion along the ramp. afreefall = 9.8 m/s2 (down) Similar Triangles!

  11. More 2D Motion: On a Ramp and Relative The acceleration vector that causes an object to slide down a ramp is not the full acceleration of an object in freefall: Only the parallel [green] component causes motion along the ramp. θ afreefall = 9.8 m/s2 (down) θ Similar Triangles!

  12. y ax = afreefall• sin (θ) ax θ x afreefall = 9.8 m/s2 (down) θ

  13. y ax = afreefall• sin (θ) Example: if θ = 20° then ax = 9.8 m/s2 (0.342) = 3.4 m/s2 ax θ x afreefall = 9.8 m/s2 (down) θ

  14. y ax = afreefall• sin (θ) Example: if θ = 20° then ax = 9.8 m/s2 (0.342) = 3.4 m/s2 ax θ x afreefall = 9.8 m/s2 (down) θ Motion on the ramp involves the 1D equations of motion, with ax given in terms of angle θ (as given above).

  15. Relative Motion

  16. Relative Motion —all motion is relative to some reference point.

  17. Relative Motion —all motion is relative to some reference point. Example: you throw a ball up as you run at a constant velocity…

  18. Relative Motion —all motion is relative to some reference point. Example: you throw a ball up as you run at a constant velocity… Relative to you the ball goes up and down…relative to a stationary observer the ball moves along a parabolic curve.

  19. Relative Motion —all motion is relative to some reference point. Example: you throw a ball up as you run at a constant velocity… Relative to you the ball goes up and down…relative to a stationary observer the ball moves along a parabolic curve. Think of a similar example: when you throw something up in a moving car.

  20. Think of an example when the moving thing is not a car but a river. You row a boat across the river but the river is moving… BOAT Your motion relative to the river… The river’s motion relative to someone on shore… Your motion relative [as seen by] someone on shore.

  21. Think of an example when the moving thing is not a car but a river. You row a boat across the river but the river is moving… A sum of displacement vectors. BOAT Your motion relative to the river… The river’s motion relative to someone on shore… Your motion relative to [“as seen by”] someone on shore.

  22. Think of an example when the moving thing is not a car but a river. You row a boat across the river but the river is moving… A sum of velocity vectors. BOAT Your velocity relative to the river… The river’s velocity relative to someone on shore… Your velocity relative to [“as seen by”] someone on shore.

  23. Example problems form the textbook: Problems 17, 22 and 29 done in class.

More Related