1 / 20

The Fun Side of Mechanics: Day Three! Countersteering

The Fun Side of Mechanics: Day Three! Countersteering. By Jonathan Abbott. Quick Review. Newton’s First Law Net Force Newton’s Second Law Friction Kinetic vs. Static Newton’s Third Law Center of Mass. Today: Countersteering.

liora
Télécharger la présentation

The Fun Side of Mechanics: Day Three! Countersteering

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. The Fun Side of Mechanics:Day Three! Countersteering By Jonathan Abbott

  2. Quick Review • Newton’s First Law • Net Force • Newton’s Second Law • Friction Kinetic vs. Static • Newton’s Third Law • Center of Mass

  3. Today: Countersteering • Countersteering is when you shift your point of contact (with the ground) in the opposite direction to help you move. • So in order to balance, you change where you touch the ground. Too much this way, ahhh! Too much that way, ahhh! Points of Contact

  4. Simon Says We are going to practice how we balance.

  5. Two ways to balance Countersteering Continuum Twist body Change Point of Contact Change Shape of Body What we are talking about today What we will discuss later

  6. First Safety! • The contact force between you and the ground can hurt! • Helmet • Wear it, love it, and it will love you back!

  7. Idling on a Unicycle: Overcompensating Move the point of contact more than the center of mass

  8. What is the physics of Idling? Think about the net force

  9. What about the Pogo? • When up in the air, twist your body so that the point of contact underneath you changes, allowing you to remain upright. • Overcompensate!

  10. You can Pogo on a Unicycle!Aka Bunny Hops

  11. A Rolla Bolla • It’s simple a board on top of a rod thing; like a plane on a cylinder. Let’s draw a force diagram (see next slide)

  12. What forces are between the board and cylinder? • What forces are between the ground and the cylinder? Let’s identify the forces in a force diagram.

  13. Let’s identify the forces between the person and the board in a force diagram.

  14. Rolla Bolla Analysis • So how does one balance? • By changing the angle of the board on the plane, there becomes frictional forces between the board and cylinder and the cylinder and the ground that together push the person to the left or right. • To balance, one has to overcompensate to stay upright.

  15. Parents – How smart are they? • When you were first learning to ride a bicycle, what advice did your parents give you? • Okay, so using what we have talked about today, how might I be able to make a left turn on a unicycle?

  16. The trick is countersteering • I have to turn to the right to make a left turn! • This way I can lean. Normal Turn right to lean Turn left

  17. Sharp turning on a unicycle • This makes it a little easier to see. • I have to turn right to go left.

  18. Beware! • For a motorcyclist or bicyclist to turn left, they will have to first swerve to the right in what is known as countersteering. • They will need extra space! http://www.flickr.com/photos/jduty/5016023830/sizes/m/in/photostream/

  19. Bikes and Scooters! • You do this on a bike, but it can be hard to see. • If you ride slowly, you may notice it more.

  20. A little harder to Unicycle • Unicycles can also fall forward or backward. • So, if leaning too far forward, speed up temporarily to get the unicycle in front and then slow down.. • If leaning too far backward, slow down until upright, and then continue forward. • It’s like “idling” while moving forward.

More Related