What you need:
Hanging items: keys, paper clips, purses, bags, hats, necklaces, jackets, etc.
Sensory tub or a set of baking sheets with items of different textured surfaces (plastic, wood, plaster, metal, string, etc.),
Container with water
Learning Goals: Science: Investigation and Discovery
Some ocean animals, like the squid, the octopus, and the sea urchin, rely on suction to help them grasp objects and/or food. Here are some activities that allow children to explore and experiment with suction cups in order to gain a deeper understanding of how suction works.
What you do:
Explain that some ocean animals, such as squid, octopus, and sea urchins, have suction cups located on parts of their bodies. These suction cups help them grasp on to objects like rocks or food. When a suction cup latches on to an object, air or water is pushed out of the cup and the outer edge forms a seal that keeps out any additional air or water. The pressure from the air or water outside the cup (which is trying to get in) is stronger than the pressure inside the cup. It pushes on the cup and causes a force called suction. Suction causes the cup to stick to the surface of the object it’s attached to.
Activity 1: Applying Suction Cups
Set up a sensory tub or a set of baking sheets with items of different textured surfaces (plastic, wood, plaster, metal, string, etc.), small bowls of water, and suction cups. Have children practice sticking the suction cups to the different surfaces. Have them test out different strategies for making the suction cups stick: which strategies work and which do not?
Activity 2: Suction Cup Strength
Have children hang items of different weights (paperclips, necklaces, keys, purses, bags, jackets, etc.) from suction cup hooks of different sizes. Which suction cup hooks can hold the greatest amount of weight? Which are limited to certain amounts of weight? What is it that causes some suction cups to be stronger/weaker than others?