The Physics of Surfing Savana Mcmillon Mr. G Period 7 Wednesday, May 9, 2012
Mass and ShapeThe surfboard and its riderboth have a center of gravity,which is related to their shapeand mass. When riding thewaves, the rider can move hiscenter of gravity to shift theboards angle in the water. Forexample, moving toward thetail of the board will cause thenose to lift up from the waterin response to catching a wave.
Newton’s 3rd LawAccording to Newtonsthird law, every actionhas an equal andopposite reaction.When a rider pushesdown one edge of theboard, that edge pushesinto the water, whichpushes back up againstthe board. As a result,the board starts to turn. (F=MA)
Gravity and BuoyancyWhen you are lying on your board in still waterwaiting for the next wave, there are twoimportant forces at work: gravity and buoyancy.Gravity: This force pulls on every atom in you andin your board—yet it behaves as if it were actingjust at your center of mass. For most people, theircenter of mass is located behind their navel in themiddle of their body when they’re standing upstraight. Your center of mass is your balance point. Buoyancy:This is an upward force created by thestill water pushing up on the board and is known asa hydrostatic force.
TorqueWhen the surfer moves back on theboard, gravity and buoyancy move outof alignment and create a torque, atwisting force, on the surfboard. Theboard rotates until the forces are
Work Cited1 http://www.exo.net/~pauld/ activities/surﬁng/ physicsofsurﬁng.html2 http://blackmagic.com/ses/surf/ papers/physicsgrm.html