It's a neat piece of science art, and it also tells us something interesting. The arrows show us that the force on the skateboard is constantly changing, both in magnitude as well as in direction. Now the force of gravity obviously isn't changing, so the reason that these force arrows are shrinking and growing and tumbling around is that the skater is changing how their feet pushes and pulls against the board. By applying a variable force that changes both in strength and direction, they're steering the board.
Skateboarding started in California in the 1950s. The first skateboards were made from roller skates (attached to a board). Skateboarding gained in popularity because of surfing; in fact, skateboarding was initially referred to as "sidewalk surfing". Initially, skateboards were handmade from wooden boxes and planks by individuals. As the sport became more popular, companies started manufacturing skateboards. Boards are also continuing to evolve as companies try to make them lighter and stronger or improve their performance.
4 amazing skateboards in one nice lot. 1. 1990's Tony Hawk Conplete Skateboard, original falcon 3 design. With Rekon trucks and firelite classic wheels. 2. Sk8mafia Lucero deck. Signed by John Lucero. Brand new deck. 3. 1031 deck signed by entire team on a brand new creepy crawl deck. 4. Brand new super rare Big Mess deck with Blast design. This deck is extremely rare and is a must have for any collector. Both the signed decks are personalized to a guy named Jason that owned a skate shop here in Grant's Pass Or. Those guys were on his wall for a long time before he went out of business. If you have any questions or concerns please let me know. Thanks for looking. Steve