LEAFLET: PHYSICS OF SWIMMING

DID YOU KNOW THAT YOU CAN LEARN PHYSICS FROM SWIMMING ? Learn about the science in: ● Moving Through Water vs. Moving Outside Water ● Diving vs. Cannonball It looks at the following questions: What is the connection between buoyancy and gravity? Why is water more viscous than air --- and just WHAT does viscous mean?! What simple machine in my body helps me swim? GATEWAY TO SCIENCE: Sports and Games http://sportscience-kathy.blogspot.com ----------------------------------------------- INSIDE p. 2 (left) WHAT KIND OF FORCES ARE INVOLVED IN ….? walking – bicycling – swimming Walking                 Lifting my legs and swinging my arms, I work against GRAVITY (and AIR RESISTANCE if I walk into the wind). Bicycling                 Because I'm moving faster than walking, I'm working against more AIR RESISTANCE plus GRAVITY. Swimming                 My BUOYANCY tends to cancel out the effect of GRAVITY. (See the center column. ) One more thing! WATER RESISTANCE slows you down.   This is because water is more VISCOUS and more DENSE than air. Well, what does viscous mean? A viscous liquid is resistant to flow. Think of molasses, honey, and ketchup! What does dense mean here?  The same amount of water (a liquid) weighs more than the same amount of air (a gas). Think of a balloon full of water vs. a balloon full of air! ------------------------------------------------------------------------------ INSIDE p. 3, center WHAT KIND OF THINGS CAN I LOOK FOR? Let's talk about buoyancy! Definition: Buoyancy: Tendency to float or rise when submerged in fluid Buoyancy is the balance between: pressure of water, pushing UP   and force of gravity, pulling DOWN When you are stretched out flat,   there is more surface for the water to push UP on. Therefore (∴) : Cannonball © vs. Diving \ With a small, concentrated surface area, you will sink! ------------------------------------------------------------------------------------------------ INSIDE p. 4 right Newton's 3 Laws of Motion 1st   An object not moving tends to stay that way unless it comes in contact  with an outside force.  An object that is in motion also has a tendency to stay  that way, unless it comes in contact with an outside force.  This tendency is called INERTIA. The tendency for a moving object (you) to stay in motion, when swimming,  does not hold up well due to water resistance. Why?  Water resistance is the “outside force” acting on the object, you. 2nd   Force is mass combined with acceleration --- or F = m∙a Let's think about simple machines.  What parts of your body work as a simple  machine to accelerate yourself and give more FORCE and speed for less effort? (Is this part: an inclined plane?  a screw?  a lever?  a rope and pulley?  a wedge?   a wheel and axle?) Did you guess that your arms and legs work as levers?   Your levers pivot at your joints;  the joints work as fulcrums.  3rd   Every ACTION has an equal and opposite REACTION.  So when you push backward  –  an action  –  on the side of the pool,  you go forward – an equal, opposite reaction. ------------------------------------------------------------------------------------- OUTSIDE, left NOTE The terms water resistance and air resistance used in this leaflet are commonly referred to as “drag.” Sports and games are the gateway to science, and YOU hold the key! Also, did you know......? Muscle is more dense than fat --- so fatter people are more buoyant. _________________________________________________________ OUTSIDE, center (this is the back of the leaflet) SWIMMING........ is just one of endless ways to gain an understanding of physics and geometry. I hope this leaflet introduces you to seeing things you never saw before – or wondered about but just didn't know where to start. Physics and geometry come into play in every activity and event going on around us. Knowing how things work can add to your performance and to your fun.   So give it a try. How? Start with the information here You may not understand everything in it right away, but for now, use what you do understand Do an online search of your own See what books or videos your library has Share them with friends, your class, your team, your scout troop Read my blog and tell others: sportscience-kathy.blogspot.com Thank you!       Kathy Hogan Information for this leaflet is thanks to: www.explainthatstuff.com/swimming-science Check it out for more on swimming science! Check the library for this book, too: Science Behind Sports: Swimming Lizabeth Hardman, Lucent Books, New York, 2012