you build the track to slow the ball down?
make it go a shorter distance?
build the fastest track possible.
build the slowest track possible.
build a track that will allow the ball or car to dip down to a lower point and then go to a slightly higher point.
draw a picture of the structure you built. explain what it does and how it works, using words and/or pictures.
draw a picture to show what you could do to the structure to make the ball (or car) go faster.
draw a picture to show what you could do to the structure to make the ball (or car) go slower.
to extend the ideas in this lesson, you 