Unit 5: Ramps and Rolling

When was the last time you played on a slide? Here’s a chance for you to revisit the fun, because a slide is just a big ramp. So grab a teaching partner, or a willing friend, and explore ramps together, both outdoors and in your classroom.

Here’s your chance to really focus on inclined planes and how things roll or slide down and off them. These hands-on activities will help you:

• Observe how things roll and slide on different surfaces
• Think about ways you can help children get the most out of ramp-and-rolling explorations, vocabulary you might introduce, questions you might ask, and ways that children can represent their discoveries
• Troubleshoot problems that might arise when the children use the materials
• Learn more about the science of inclined planes

Activities

As you explore, reflect on how you could best introduce and adapt activity ideas to suit your children and your environment. The questions below are intended to spark those reflections. 

Outdoor Ramps

Gather several balls of different weights and sizes (including marbles); small classroom objects, such as a marker, building blocks, and chalkboard eraser; cardboard tubes, PVC pipes and/or flexible hoses; boxes; lengths of cardboard or wood (for building ramps); and a clipboard, paper, and pencil for taking notes. Then head outside!

Survey the Possibilities

• Walk around your outdoor play area and search for ramps and other sloping surfaces. Check out playground equipment (slides, seesaws, roofs on playhouses, etc.). Do you have a sandbox in which you could build a hill of sand? Look for paved walkways, grassy and not-so-grassy hills, access ramps to the building, etc.
• Not sure if a paved area is flat or inclined? Try placing a marble or ball on the surface and see if it rolls and which way.

REFLECT: Which areas are safe for rolling balls and other objects? How might you create a barrier so balls do not roll too far?

Roll, Slide, or Stay Put?

• Gather some small outdoor objects (a stick, pinecone, stone, etc.). What do you think will happen if you put each object on a slide or other inclined surface? Will it roll? Slide? Stay put? First, make a prediction; then try it out. Try each object several times. Does it always move the same way? For example, what difference does it make if the stick is pointing down or pointing across the incline? Discuss any surprises with your partner.
• Continue the experiment with your collection of small classroom objects. Include several balls and a cardboard tube.
• Sort the objects into groups: those that rolled down the incline, those that slid, those that both rolled and slid, and those that just stayed put. What is similar about the objects in each group? What words would you use to describe their shape, texture, rigidity or floppiness, etc.?

REFLECT: What do you think the children will notice? How might you record the words they will use? What open-ended questions might you ask that will help them focus on the characteristics of the objects and how the objects are moving?

Explore Different Surfaces

• Try to find a paved area or walkway or a slope—if possible, one with grass or dirt next to it. Place a ball on the paved surface and let it roll downhill. How far does it go? What do you think causes it to stop?
• Place the same ball on the grass or dirt next to the pavement. How far does it roll on this surface? What do you think makes it stop? If you have two similar balls, you can try “racing” them on the two surfaces. What words come to mind as you try to describe the movement of the balls?
• What happens if you change the surface texture of the dirt or grassy area by placing a large piece of cardboard or plastic on top and then letting a ball roll down? How does the movement compare to the ball rolling on the paved surface?

TIP: If you don’t have inclines outdoors, children can still explore the way things move on different surfaces by rolling the balls on flat surfaces. Have them try rolling different balls on different surfaces (pavement, grass, dirt, or pebbles) to decide which surfaces and which balls are best for a game of bowling.

REFLECT: What materials would you want to make available when you do this exploration with your children? How could you help children record and compare how far a ball rolls on each surface?

Explore Different Balls

Try rolling balls of different sizes and weights down paved ramps and grassy hills. What do you notice? Think about the vocabulary you are using to describe the balls and how they are the same or different.

Build Ramps

Outdoors can be a great place to build large-scale ramps for balls. Use cardboard tubes, flexible hoses, pieces of gutter, wooden trim or planks, PVC pipes, etc., to build a long track for a ball to roll down. What adjustments do you need to make so that a ball rolls all the way from one end to the other?

For an added challenge, try building a track where the ball rolls uphill for a short stretch. What do you have to do to the track to get the ball to roll to the end? Or find a way to incorporate a playground slide or hill into your track construction.

REFLECT:

• How might you engage children in building a large-scale track? What materials would you provide? What practical help might they need?
• What do you think children will experience and learn from this activity?
• What words will they need to know in order to talk about their work and share their discoveries?
• What are some ways they could document their work? For example, they might create a collage or build a 3-D representation of their construction, using crafts sticks or yarn to represent ramps and circles or stickers to represent balls.

Indoor Ramps

Roll or Slide?

• Put a piece of foam core or cardboard on the floor and place a small object in the center. Experiment to find out how much you need to slant the foam core or cardboard before each object starts to roll or slide. What do you notice? Try this with a number of objects, noting which ones roll and which ones slide. What is it about the object that affects how it moves?
• Note that a marker will roll if it is placed sideways across the ramp, but it will slide if it is placed pointing down. Can you find other objects like this? What happens if you place those object diagonally across the ramp?

REFLECT: What do you want children to notice? What objects will be most interesting for them to experiment with? What language might you model and encourage them to use with this activity?

Unusual Ramps

• Your legs can make a good ramp for a rolling ball. So can other parts of your body. See how many different “body ramps” you can build.

REFLECT: What do you think children will experience and learn from this activity? How do you think it would work best in your classroom—as a whole group, small group, or partner activity?

• Try using a long, wide, flexible hose as a ramp. Use a large marble as your ball. What new possibilities do these materials introduce into your exploration of ramps? For example, see what happens if you make the bottom end of your ramp curve up.

REFLECT: How do long flexible tubes lend themselves to partner work? What sort of games can you and your teaching partner create?

Less Steep and Steeper

For these explorations, you will want to have enough space in front of the ramp for the ball to stop rolling on its own. A hallway, for instance, is a great place to set up a ramp for rolling balls.

• Explore how far a ball rolls as you gradually increase the steepness of a ramp. Get several equal-length pieces of cardboard or foam core to use as ramps and a supply of equal-size building blocks. Build a series of ramps side by side. Prop the first ramp up on one block, the second ramp on two blocks, etc.
• Try rolling a ball or tube down each ramp to see how far it goes. To make this a fair test and control for all the variables, it’s important to just release the ball at the top of the ramp—don’t give it a push. To ensure that you release the ball from the same place each time, you can draw a start line at the top of the ramp and use a ruler as a starting gate. (Set the ball behind the ruler, then lift the “gate” and let the ball roll.)
• >Set yourself a challenge. Try to get a ball to roll down a ramp and stop at a certain point on the floor. Adjust the steepness of the ramp until you get it to stop at that point.
• Place an obstacle, or a row of obstacles—a tower of small blocks, a paper or plastic cup, or toy cars—a short distance from the end of one of your ramps. Roll a ball down the ramp. What happens when the ball hits the obstacles? You can extend this into an investigation by using a differently weighted ball or changing the incline of the ramp and observing the results.
• Change the steepness of the ramp. Let the ball roll down and hit the obstacles. How does the steepness of the ramp (and thus, the speed of the ball) make a difference?
• Use a heavier and a lighter ball on the same ramp. Let the balls roll down and hit the obstacles. How does the weight of the ball make a difference?

Science Concept: Angle of Incline

The steeper a ramp becomes, the more quickly an object will roll or slide down the incline and the farther it will roll after leaving the ramp. A ball rolling down the steeper ramp (the one propped on the taller box) will travel farther than a ball rolling down the less steep ramp.

Science Concept: Knocking Over Obstacles

A ball’s ability to move or knock something over depends on momentum. The momentum of a ball depends on how fast the ball is going and how heavy it is. If two different balls are rolling at the same speed, the heavier ball has more momentum. If two balls that are the same weight are rolling, the ball that is rolling faster has more momentum.