Activity

Playground structures Forces and energy

Summary
Use playground equipment outdoors to demonstrate forces and energy transfer.
Science content
Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6)
Physics: Energy forms, Conservation of Energy (1, 3, 4, 5)
Materials
  • playground equipment such as slide, swings, climbing structure, spinning structure etc
  • optional friction on the slide activity: pieces of fabric with different textures, large enough to sit on
Procedure

Types of Motion for younger students
Ask students to use their bodies and the equipment to move in different ways: spin, roll, slide, lift, fall, bounce, swing. They can also be given balls to use. They can use a worksheet to check off each motion, and draw the equipment they used.

Forces for younger students
Before the students use the equipment, discuss what a force is: something that can move an object, or stop it from moving. A push or a pull.
Sometimes a push or a pull is when things are in contact with each other, like my hand pushing the ground , or my linked fingers pulling against each other (demonstrate and ask students to try).
Sometimes the force does not contact the object it moves. Gravity pulls things towards the ground, even if it is not touching them.

Organize the students into groups, and show them the pieces of equipment that they will be using.
For example, divide playground equipment into two or three stations, then add one or two other stations (e.g. bouncing balls, balancing pole).
Ask students to feel the forces on their body, find out why they move up or down, what forces make them move.
As the students are using the equipment, visit each station help students feel a force as it happens.
After all students have visited all stations review what they found.

SLIDE forces, questions to ask and discussion points:
What are the pushes and pulls as you use the slide? Why can’t you slide up? [gravity is pulling you down, but you can walk up and push against it]. What happens if you start half way down the slide - how do the forces change?
As you climb up the steps you work against gravity, giving yourself energy. Gravity pulls you back down.
Friction between you and the slide slows you down, so the clothes you wear or how wet it is makes a difference to how fast you can go.

SWINGS forces, questions to ask and discussion points:
How do you start off. What kind of force? (what is pushing or pulling)?
Why do you stop at the top of a swing. What force makes you stop? [gravity pulling you back down].
How to get higher?
Push of your foot against the ground, or someone pushing you makes you start to move. You can pump your legs to make yourself go higher (putting your legs higher gives you more height energy, like the slide).
Gravity pulls you back down. The higher you went the longer you have coming down and the faster you will go.

CLIMBING NET forces, questions to ask and discussion points:
What forces make it stay up? Look at it as a structure, like a bridge or building.
You tread on the rope and push on it. Why doesn’t it move much?
Can you feel the forces of someone else moving around on the net?
Discussion:
The ropes constantly have pushes and pulls on them. They pull against the fasteners which pull back on the ropes. This keeps the whole thing taught.
If you move, you make a push, which transmits through the ropes to the other end of the structure, where someone else can feel it.
Bridges and other man-made structures are built to spread out the forces on them so they stay up. They have lots of cross braces connecting all the parts together.

The lesson adds in other stations.

Energy transformation for older students
Divide the students into groups, to rotate through the different pieces of equipment. List different kinds of energy and discuss the kinds of energy that might be used on the equipment. Then as the students use the equipment, talk to them about the energy types that are being used and how they are converting between each other: motion energy as their body is moving, potential energy as they get higher up, heat energy made in their bodies as they are moving, chemical energy stored in their bodies that can be converted to all these other kinds of energy.

A SWING has motion energy as it moves, which changes to potential energy (or "height energy") as it gets higher. Each time the swing goes back and forth, it has the most motion energy at the bottom of the swing, and the least when it comes to a stop at the top of its swing. It has the most potential energy when it is highest and the least when it is lowest. Energy changes between motion and potential energy forms and back again, as it swings back and forth. This demonstrates that energy can be transferred, but is always conserved.

A SLIDE converts potential energy to motion energy. As you climb the steps you gain potential energy (from gravity pulling on you). As you slide downwards, the potential energy reduces, and is converted to motion energy.

Additional force of friction on the slide:
A slide is an inclined plane, so the gravity pulling you down presses you onto the slide. As you move, there is friction between you and the slide. Friction is a force that slows things down as objects rub together. The rubbing generates heat energy, which is quickly lost to the air. Students with bare legs may feel that heat energy made from the friction between their body and the slide. Energy is transferred but always conserved.
As some of the potential energy you had at the top of the slide is lost to friction as you slide down, you descend more slowly than if you simply jump from the top of the slide.
Slides are made of smooth material to reduce friction. Students can experiment sliding on different pieces of cloth, or onto of jackets etc, to experiment with which materials reduce the friction most, and allow them to go the fastest down the slide.

A SPINNER has rotational energy.
Ask students to compare how fast they move when they sit on the outside or the middle of the spinner. They move much faster on the outside as they travel further in the same time as someone sitting in the middle of the spinner (look at one rotation to compare).
You can feel the force pushing you outwards as you hang on to the spinner. If you let go of the spinner, you would fly off, but in a straight line from your direction of travel, rather than straight outwards (as dictated by Newton's First Law: objects will keep moving in a straight line unless acted on by another force).

The lesson adds in other stations.

BALANCING POLE

Notes

Use this activity to study gravity: students are challenged to use the playground equipment and list/draw all the times they use gravity. e.g. gravity pulls students down the slide or down to the ground when they jump off something; gravity brings a swing back down after a student has used the forces of their bodies to push it up.

Grades taught
Gr 1
Gr 2
Gr 4
Gr 5
Teaching site
Dorothy Lynas Elementary
Elsie Roy Elementary
Gordon Elementary
ingridscience afterschool