Up hill Roller

goes against gravity?

 

 

 

Category - Force & Energy

Key Idea - Inclined Planes

 

Purpose - Sometime the inclined plane is not where you think it is.
Nature -  Demonstration
Materials -  Two large plastic funnels, two metre rules, five copies of a thick text book, masking tape.
Method - 
  1. tape the two funnels together with the large opens touching.
  2. pile three text books under on end of the metre rulers and two under the other.
  3. The metre rules need to fixed with masking tape so that they are close together at the lower (two book) end and further apart at the higher (three book) end.
  4. If you have fixed the rules correctly, you can place funnels at the lower end and they will roll up to the top.  It may take a little adjustment to get it working well.
Safety - Nil.
Explanation - If you look at the funnels you will see that they are also made out of steep inclined planes.  Because of the way you have arranged the rules, when the funnels are placed at the two book end, the centre of gravity is higher than at the three book end, and it rolls down the funnel, and up the ramp. 
Notes - It's best to have this set up ahead of time because it can take a while to get the adjustment working well.