How does friction affect high jump and cycling?

Question

Annoying homework question. If you can only help with one, that's fine. But I'd prefer to get answers on both @_@

Answer 1

Friction in high-jumps allows you to slow down as you convert horizontal speed into vertical speed (you could consider a pole vaulter as having immense friction when the pole stops as it hits the pocket.

In cycling the friction of the alphalt on the tires is what pushes the times forward.  Without friction, the wheels would just spin like a teen burning rubber in a car.  The melting rubber greatly reduces the friction in that example.