Kids and Things in Motion: Primary Physics
One of the most fascinating things for young children about the physical world is what happens when they act on something and there is a consequence. Those actions can include pushing, pulling, rolling, throwing, winding up or “letting go”. Those “somethings” acted on can include toys shaped like a car or truck, marbles, balls, balloons, paper airplanes, even oranges or Cheerios. The consequence of dropping is that the object comes to a stop when it hits the ground. Alternatively, something pushed can roll, at first accelerating and then slowing and eventually coming to a stop. Other actions may influence the direction of the roll or flight path through the air. If pushing or rolling, variations regarding what surface the object is moving on (flat or inclined), the texture of the surface (tile versus a rug), and the weight of the object will influence speed and distance covered. There are an endless number of possibilities, and it is easy to see why children find the interaction of things (matter) and forces or energy fascinating.
If you haven’t already sensed this, the actions and consequences just described represent some of the most basic concepts in physics or the science of energy and matter. Young children regularly experiment with things in motion. Now it is your turn to add some additional dimensions to these frequent and spontaneous explorations. For this post, we will be talking about forces on objects, where the forces are either gravity or force the child exerts. Even if the child acts, gravity is still operating and is the “ever present” force acting on all objects. So, you may need to help your child acknowledge the role of gravity whenever possible. She probably already has a sense of gravity. After all, if you drop something, it goes down. Even infants intuit gravitation force.
As your child’s guide in play, probably the most important thing to understand is to be certain that it is your child’s actions that produce movement. When your child does something versus being a passive observer, he will be more committed and interested in the consequence. Moreover, the more directly the action is linked to an observable consequence (not one that is barely noticeable) the better. Learning is not an observational sport, so please do not demonstrate (except perhaps if an activity is unsafe). Rather follow your child’s lead and encourage her own actions, hinting at variations on the force (push harder or softer) or introducing new objects to be moved (What about if we tried (an alternative object)….?).
There are some great toys that capitalize on children’s fascination with objects and movement and if you already possess these then play on. If not, no worries as you probably already have the ingredients at home or in your yard for a great ramp or chute. Bring out any blocks, boards, toilet or paper towel rolls, perhaps some tape, and your child is ready to rock and roll.
For those children who take an interest in sports, their actions (kicking, throwing, heading, batting, swinging a hockey stick or tennis racket) are producing consequences, although not always as desired. Coaches talk about practicing these actions (shooting, dribbling, passing, fielding), which you too can encourage. But you can also capitalize on an interest in sports to discuss forces, energy, and matter, or the variations in actions that can produce different outcomes.
Why do things fall down? (Gravity?)
Why do things move across the ground or track (or be more specific such as why do they roll, slide, or glide) (gravity is operating here too to keep the object on the surface as opposed to floating up)? Why do things move down a ramp (a combination of gravity and a force provided by your child)?
Do all things move? If not, then why do some things move and not others?
How fast(speed) or how far (distance)does something move?
Why do things stop moving?
Can I do something to stop something from moving or make it move faster/slower?
Once again, hours can pass in play involving making things move. Perhaps with questions, you can encourage your child to find the language that describes the movement. So something can go faster, slower, farther, or be barely moving or stopped. For things moving through the air, find words to describe their flight path – or they can glide, sink, float, or crash. Things can move directionally, or up, down, sideways, or around a curve.
Relevant words include reference to the type or amount of force. I pushed really hard, or hardly at all. I blew on it so it moved, or I let it go on the incline. I kicked it as hard as I could versus I barely touched it.
It’s okay here to use the adult terms to describe what is observed or something is accelerating or decelerating.
Observe the consistency of the movement. That is, did it move in a straight line, or perhaps the object wobbles or swerves.
Toys capitalizing on movement such as trucks, trains, tracks and gadgets with marbles, are just exhilarating to play with. If you as the guide try to make suggestions too early, sheer joy may overwhelm the desire to look for words. So, maybe gauge the level of excitement and wait until giddy gives way to a little more focus.
Here the language one is looking for is faster than, slower than, farther than, less far than. You can invite your child to compare the simultaneous movement of two objects, or perhaps the object moving one time and then again when your child has repeated the initial action or perhaps added a variation (pushed harder, blew on it versus pushed it, or altered the incline of the track).
Measure and Experiment
Not much you have to do here except make some interesting materials available for play and experimentation. Planks of wood, pieces of molding, parts of gutters, heavy cardboard, toilet paper or paper towel rolls can be used to build “tracks”. Alternatively, just “move” things across grass, the floor, or roads built in sand or dirt. Roll or push toys (with and without wheels), marbles, balls, acorns, pinecones, M&M’s, pebbles, shells, or experiment with any number of spherical items in your home.
Eventually, ask your child to examine a variety of objects and make predictions about what will move or not move (they all will drop because of gravity), or under what conditions will something move or not. A ball can roll across a flat surface, but do other objects need an incline to move? Something may roll if placed in one position but not if turned in another position. Think, for example of a pen or a straw which if positioned vertically on an incline won’t move.
Set up ramps side by side and predict which items will make it to the bottom first.
Add other materials to the surface of a ramp, such as a dishtowel, tape with the sticky side up, or perhaps something that is easy to clean off such as dish soap. How does changing the surface of a ramp impact the speed of the object rolling?
If using the toilet paper rolls or paper towel rolls, tape these together to extend the tube. Tubes from wrapping paper or map tubes are good choices. These are longer and hold up better to multiple experiments. Invite your child to hold those tubes at different heights/angles. A marble or small ball in the tube will behave differently depending on these variations.
Vary the height of the ramp or the angle of tilt. With which angle does an item move fastest? Measure the angle (use a protractor -flash back to geometry class) or measure the time it takes for the item to get to the bottom.
As noted earlier, your child learns best when he is responsible for the action. But learning is also enhanced when your child can experiment or vary those actions. Some variations have already been mentioned. So when it is the right opportunity to make a suggestion, if your child is not generating his own alternatives, suggest standing and pushing versus sitting and pushing, blowing with one’s mouth alone versus blowing through a straw, rolling or throwing something without an arm swing or add a swing (think of bowling or pitching in baseball). If you are playing along, you can demonstrate variations.
Measure the distance that the object moves, and compare these distances across the variations in activities. If measuring or comparing distances, you may want to consider an agreed upon “starting line.” This line is where your child places the object at the top of the ramp or at the start of a track. Your child can measure from this line to the point where an object came to rest (things stop rolling because of gravity and friction). You might also suggest that an item be rolled several times to determine where it stops, before comparing it to an item that is bigger, smaller, heavier or lighter, or whatever the experiment calls for.
If playing with a toy truck or vehicle and you can put something in the “back” of it, suggest changing its weight by adding pebbles (or something that won’t be hard to clean off of the toy or from the floor). Observe its motion. How is it alike or different with more weight? How far does it go relative to when it rolled without the additional weight? You can find ways to add weight to other items as well, as long as they can still roll.
If rolling something around consider doing it on paper and putting a splotch of paint on the object so that it leaves a mark each time it completes a full turn. Measure the distance between the marks or count the marks. Try this with objects of different sizes and compare the rolling patterns.
Go to a playground and swing on a swing. Discuss the force it at takes to start the swing going. The force can either be a push from a parent, or “pumping” one’s legs. If the force is stopped, or there is no pushing or pumping, how long does it take for the motion to stop? Does the swings arc or the time it takes to stop swinging vary if the passenger is you versus your child?
Blow up a balloon and hold the neck. Ready, set, let it go! What is the energy or force causing the balloon to move? (Blow up the balloon again and let the air out while your child holds his hand under the neck. What does he feel? The air escaping is pushing against the outside air that is the force behind the movement of the balloon.)
Create art with or depicting things that move.
Some of the items your child may have been playing with such as toy cars or trucks have wheels. Wheels are tools that assist in moving objects. Look around and find things with wheels. Can you name some things? The wheels themselves do not make that object move, however. Some force is necessary. What force moves a wheel barrel, a bicycle, or a train?