Play, Physics and Sports: Children and Learning
The Guiding Curiosity activities assume that you as the person doing the guiding are building on or extending a child’s play. I am not sure I reiterate this point enough in describing the activities; so let me do so now.
Play is a foundation for learning – learning in childhood, adulthood, and even among our animal friends. Across these groups, play behaviors are different, but you would recognize them because they share some common features. During play, the individual person or animal is motivated, stimulated, engaged, and having fun. While playing, we are free to experiment and take risks; both actions are crucial for learning.
All areas of learning during childhood benefit from play. One that you may not have thought of is exploring some of the basic principles in a branch of science known as physics. Among other natural phenomena, physics explores motion and/or physical interactions between objects. Whether with toys specifically designed to demonstrate these ideas or just rolling trucks and cars on a track, children are familiarizing themselves with some critical concepts about the physical world.
Through observations, playful experimentation, and repeated exposure to a phenomenon, scientific ideas and theories begin to emerge. This process is gradual, the theories intuitive, and the child may not have the precise scientific language to describe these experiences or the associated concepts, but familiarity is what the child will need to build on understanding either on his own or with the help of parents and teachers.
Simply put, imagine being asked to learn about the variables (weight, volume, design, and material) that contribute to whether an object floats or sinks if you had never played with toys in the tub. How can you understand erosion (the forces that move rocks and soil) if you have never poured buckets of water over mounds of sand or dirt or played with the garden hose? Watching a spinning top establishes torque and centripetal force.
Children who “play” sports may also benefit if there is awareness of some of the concepts in physics. I am distinguishing “playing” sports from free, child-directed play as, these days, most sports activities are initiated and controlled by adults. Even pick-up games are rule driven, and not entirely free in the sense that the child is inventing the play scenario and going where her imagination takes her.
I don’t want to impose a science lesson at the risk of undermining the enjoyment of sports as either a player or watching a game with friends and family in ballparks or on television. But, you may have an opportunity or two to sneak in a term or introduce a concept, so I am writing this to just open your eyes to that possibility. Remember that you are capitalizing on your child’s observations, questions or comments and not imposing a lesson. With the Olympics coming up this summer, if you enjoy watching them as much as I do, you will have numerous chances for slipping in a reference or asking questions and prompting curiosity.
So here are some concepts in physics that relate to sports. Ask your own questions to focus your child’s attention on something, such as “I wonder why….” Use the scientific language freely and frequently, as this is how children learn those terms.
A key area of physics covered for younger children are the concepts of Forces and Motion. Closely related to these ideas are gravity and friction. Can you begin to imagine how to work these concepts into a conversation or two?
Force: A force is a push or pull upon an object (or person). Either the push or pull results from the object’s interaction with another object (or person). Whenever there is an interaction between two objects, there is a force upon each of the objects.
There are non-contact forces (action at a distance forces), such as gravity. That is, gravity is operating but not directly on the object or person. Gravity is important in sports and we’ll discuss it more specifically in a moment.
There are also contact forces, including applied, spring, and frictional. Friction will get its own mention momentarily. Applied force or the force applied directly to an object or person is the most common in sports. Spring forces, though less common, can be identified.
The concept of an applied force is easy to experience in sports. Kicking, throwing, shooting or batting at a ball. Cyclists push pedals. Swimmers’ muscles push their arms in strokes and legs to kick, which create the force to propel them through water. In the common freestyle method legs are less important than the arms for forward thrust, but they help to keep the body level in the water and reduce drag. A swimmer’s hands are also critical sources of thrust. Canoeists apply force to a paddle. Sailors apply force to a tiller to steer the boat. What other direct contact forces can you and your child identify?
What force causes the gymnast to spin on the high bars or the uneven parallel bars? Think of the actions prior to the spin or running, jumping or diving. The spin itself is a force thrusting the gymnast into the next maneuver.
Sprinters also rely on ground force reaction or their feet push them off the surface of the track. Gymnasts push themselves off of the mat or balance beam. Swimmers find some help in the density of the water, but the wall of the pool is where they will get the biggest reaction when they do a flip turn pushing themselves in the other direction.
Athletes may rely on their physical strength in combination with other forces. Cyclists use the force of their legs to push the pedal and then amplify that force with the aid of mechanical help from the various gears on the bicycle.
Spring forces also assist athletes in several different sports. In order to get work (defined as force times distance) back out of a spring, first, you need to put some energy into the system. A diver gracefully flying through the air and spinning about is taking advantage of the force of their initial upward leap which combined with the added assistance of gravitational force when the diver comes back down on the board. This puts energy into the diving board by pushing it back down just prior to takeoff. This energy is recovered as the spring force pushes the diving board and the diver upward so he can execute his dive.
Archers also rely on a spring force. First energy is put into the system by pulling the bowstring and notched arrow back which also flexes the bow. When the bowstring is released the spring force of the bow and bowstring performs work by transferring this stored energy to the arrow propelling it forward to its target.
To stop something you also need to use force. For example, catching a ball involves pushing back in order to stop the forward motion of the ball.
Motion: Motion is the act of moving, changing place or position. When we think of sports we tend to think of our bodies in motion. When you do a somersault, your body is in motion. You move from one place to another.
Our bodies in motion may also cause another object to be in motion. A tennis player’s body in motion causes the racquet to swing or also be in motion. That racket cannot swing by itself. Once that racket swings, it too has energy that is then subsequently transferred to the tennis ball.
Canoeists’ and Kayakers’ bodies in motion, or paddling, propel their boats forward.
Either our bodies or that other object (think of things thrown, hit or kicked) when in motion is defined by its speed, time, distance, velocity, and acceleration.
Speed is equal to the distance covered divided by time, or S=D/T. If still learning addition and subtraction, your young child may not be ready for the mathematical operation of division yet, but he still probably understands that the winner of a swimming or running race covered the prescribed distance in the shortest amount of time, thus moving the fastest amongst his competitors.
You can talk about the concept of distance in all sports. Gaining a yard in football. Hitting a home run in baseball means the ball travels beyond a certain distance (depending on the park). The distance to be covered, for example, the 5,000 or 10,000-meter track events defines many Olympic events. Another less obvious distance is how far you have to jump in the long jump, or how high you have to jump in the high jump, or even how high you can vault using a pole to clear the high bar. The winner is who can jump the farthest or clear the highest distance.
Distance covered is also related to force exerted. The harder something is hit (pushed) the further it will go. All other things being equal, the more force used to move something, the greater the distance it will move.
Velocity is often confused with speed. Both are a measure of distance covered over a unit of time. Although they are very similar, there is a subtle difference. Velocity includes the concept of which direction an object is moving. For example, when you say a car is moving at a speed of 30 miles per hour, it could be headed in any direction. However, when you say a car is moving west at a velocity of 30 miles per hour, you are presenting more information.
An object or person at rest has zero velocity.
Acceleration is the rate of change in velocity over unit of time. Change is the key word here. Going fast does not equal acceleration. Going faster and faster over time does. Sprinters do not start off at their top speed, they have to accelerate from zero to their best speed during the race. We can only accelerate if a force is applied. A falling object accelerates too, in which case gravity is the force.
We can also accelerate if we change direction, thus running around a track at a constant speed qualifies as acceleration, as the distance and directions along with the runner’s velocity. The cyclist accelerates around the velodrome. A kayaker accelerates when navigating down the river course, changing direction to find the path of least resistance or dodge obstacles.
Force of Gravity. This one is easy as most children already get this idea. Gravity is the force of attraction between two objects of different sizes (earth is an object that attracts). See a whole post dedicated to gravity at http://guidingcuriosity.com/gravity-first-physics/.
After a batter hits a baseball, where does it go? That basketball that is shot at the hoop, what happens to it? Something or someone may alter its trajectory, but if not, it will fall back to earth.
Track and field includes numerous options for talking about gravity, or think of Discus, Shotput, and Javelin throws.
Divers jump up on the end of the diving board and go where and why?
High jumpers have one basic obstacle that keeps them from being “able to leap tall buildings in a single bound” (thanks, Superman), and that obstacle is gravity.
Gymnastics is a sport full of evidence of all things central to physics. But begin with gravity as a central idea.
In volleyball, the ball will eventually fall back to earth, but the players add additional force keeping the ball aloft. A similar example is a header in soccer, the ball that is kicked will follow a projectile path unless someone introduces their head and has contact with the ball.
These latter examples represent Newton’s First Law of Motion. Or every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. That is, the volleyball or soccer ball would continue on the same directional path at the same speed unless it is acted upon by another force. Remember the ball-catching example? The outside force is applied by the glove that stops the ball.
With the information we have covered so far, perhaps you and your child are also ready for Newton’s other two laws.
Newton’s Second Law of Motion posits the following: the acceleration of an object is dependent upon two variables – the net force acting upon the object in the direction of motion and the mass of the object. The acceleration of an object depends directly upon the net force acting upon the object in its direction of motion, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. The harder you hit a baseball the further it goes. As the mass of an object is increased, the acceleration of the object is decreased. A shot putter using the same force could throw a 5 pound shot farther than a 10-pound shot.
Newton’s Third Law of Motion posits that for every action, there is an equal an opposite reaction. Think of the swimmer’s hand or the kayaker’s or rower’s paddle. The hand or paddle dip in the water and are pulled back. Those hands or paddles are exerting a force on the water. But the water exerts an equal and opposite force thus thrusting the swimmer or individual in a boat forward.
Force of Friction (or Drag which is the friction between a solid and a liquid or gas): Friction is both an athlete’s friend and foe.
As a foe, friction tends to work against motion or act as a drag. Can your child identify the elements that may slow performance that athletes must learn to cope with?
Wind resistance (drag or friction) is a constant in cycling and running. Knowing that wind is resisting our best attempt to move faster, how can we deal with it? Cyclists curl around their bikes, reducing their size. Runners keep their arms close to their bodies.
Swimmers, canoeists, kayakers, sailors all cope with water resistance and do everything they can to reduce it.
How can friction be an athlete’s friend?
Friction keeps the soles of our shoes from slipping. Runners rely on getting good traction from their running shoes, so all their energy goes towards motion, not slipping. A cyclist could not stop her bike without a good brake which relies on friction.
So, with this little bit of information about physics, and you get your child to focus on forces and motion? Can you drop a hint, notice a force, point out a motion? Be that science name dropper…use terms friction, gravity, force, and motion.
A final thought on children, participating in sports and learning.
Playing at sports results in learning about the natural world, so long as a coach or too much competition does not stress the child. Developing doubt or losing confidence in one’s ability will also prove to be an obstacle to learning. Keep an eye out for stress or losing confidence as either will undermine the value of participating in sports.