AboutRalph Salier-Hellendag Expertise Science Fair Judge for many years and experience with robotics, biology, chemistry, industrial processes, metalurgy and metal forming.
Experience Science Fair Judge for many years and have helped several students get to state level competition. Most recently 2 of my students received state level awards and one went on to the nationals in Washington DC.
Education/Credentials BA Archaeology - Anthropology
MA Business Anthropology
Question How exactly does sliding or rolling friction have to do with snowboarding?
Answer Hi Billy,
The interface between the board or ski or sled and the snow, water or sand is the key to the speed, manuverability and control you have on these fun rides.
The control comes from how we distribute our weight on the board. If we lean into the board then our weight might place enough force in that direction to over come the friction holding the board in place between the snow and t he board. Once moving forward and down hill, the change in weight distribution with then allow you to manuver the board and even stop. The friction between the board and the snow is what allow this t o happen.
Rolling friction on the other hand works better with skate boards and dune surfing. With dune surfing, the sand rolls down the dune carring the board with it. it is for this reason that the control over sand surfing is really hard since the interaction is operating on ball bearings rather then on a "solid" like snow or water. As the sand rolls or as the wheels roll on a skate board, only a very tiny surface is in contact with the friction surface. This means that both an external forces is needed to start the motion and stop it. On sand this is really hard to do. That is why so many sand surfers end up getting hurt at the bottom of the dune since stopping is next to impossible.
With skate boards, the foot is the break and the body does the manuvering.
