In reality the skateboarder isn't a simple particle: assume that his mass in a deep crouch is concentrated 0.75 m from the half-pipe. if he remains in that position all the way up, what initial speed does he need to reach the upper edge?

Imagine that you have two balloons (or, better yet, actually inflate two balloons, if possible). create static electricity around one of the balloons by rubbing it against your hair or your sweater and then bring that balloon close to the other balloon, which has not been charged. try this with at least one other object—and for variety in the discussion, avoid using an object already described by your classmates. then, for your initial post to the discussion, answer the following questions: what happened with the two balloons?