Things to think about
Things to think about There may be more than one property to consider when designing and making objects such as umbrellas, e.g. what it looks like, if the material is flexible, as well as if it is waterproof. An umbrella needs to be waterproof but a waterproof material that does not fold will not be any use at all. If no-one likes how the umbrella looks, or the material is too heavy, then it will not be used. It is helpful to provide materials such as plastic, foil and wood so that children can explore and discuss their suitability. Water will sometimes sit on top of some fabrics but when they are touched the water goes through. Thick, soft materials, such as wool and sponge, can get waterlogged even if very little water drips through. In science, the word material is used to describe the substance from which anything is made. Fabric is one type of material. Metal, plastic and glass are also materials. Take it further USELESS UMBRELLA Dripping coloured water onto the material, placed on top of a paper towel, can make it easier to judge how much water has come through. Children can measure the width of the watermark. USELESS UMBRELLA You could put the fabric over a container and see how much drips through in a certain amount of time and/or when touched. Keywords • Materials • Waterproof • Liquids. Watch out! Mop up spills to avoid slippery floor. Warn children not to squirt coloured water at each other. British Science Association Registered Charity No. 212479 and SC039236 34
Useless Umbrella Activity Card Aunt Stella is in a tizzy. She has been invited to a party at Buckingham Palace. “Wow!” say Cosmic and Gem. “You must be very important.” USELESS UMBRELLA “Have you got a new dress,” Cosmic asks, “and a new hat?” Aunt Stella goes to her wardrobe and pulls out a rainbow coloured dress and a bright purple hat. “You’re going to look fantastic,” says Gem. “Do you have an umbrella too, in case it rains?” Aunt Stella nods and goes to the cupboard and pulls out a huge, rainbow coloured umbrella to match her dress. “Here it is,” she says. “It’s enormous! Can we try it Aunt Stella?” shouts Gem, as she rushes outside to open the umbrella. But it’s raining outside and no sooner has Gem opened the umbrella than drip, drip, drip, rain is tumbling on her head through the umbrella. The umbrella is full of holes! The umbrella is useless. “What am I going to do?” says Aunt Stella. “I don’t have another one.” “Don’t worry Aunt Stella, I am sure we can fix it for you,” says Gem. “We just need to find something waterproof.” 35
