Ever wondered why if you drop a steel screw into a bucket of water it will sink to the bottom but a huge steel ship carrying a heavy load can float on the ocean?
This fun and creative science experiment using aluminium foil boats will help teach your kids about the density of objects in water combined with a great craft activity. Get the family together to have a good time with science and water with this fun and informative experiment.
You will need:
Lots of aluminium foil
Paper and pens
A ruler or measuring tape
A bucket and/or bathtub with water in it (or anything that will hold water)
Optional: other waterproof objects to try and float for fun
Optional: dry rice and a measuring cup
Design Your Foil Boats
The idea of this experiment is to explore how density, or mass per volume, of a ship (and what it's carrying) compares to the density of water. Therefore, you should each make a few different boats that vary in sizes, with different lengths, widths and depths, that will support your objects. Use the ruler to decide your measurements when you are creating your blueprints for your foil boat as this will make it easier to cut the pieces of your foil. Get creative with your designs; there is room to draw or paint on the foil to make your boats unique and funky before sending them afloat.
Making Your Boats
Using your designs you can cut your foil pieces to the measurements you require. Remember when cutting your pieces that you want to fold a single piece into the bottom of the boat shape so you need to calculate the length of the bottom plus the height of the sides to turn them up. Alternatively, you don't have to have specific measurements if you would rather freely cut but make sure your boats look very different in size. Once you have your foil piece, fold the sides up to create a bowl-like shape and mould the foil into any boat shape that you would like. Reinforce your boats with sticky tape if you need to, to cover up any leaks or holes in your boat. Then once you've jazzed them up with stickers, drawings or anything else you would like to add to tell them all apart then you are ready to get down to the science.
Adding Your Pennies
The simple version of this experiment would be to see how many pennies each boat can hold before it sinks, and then see if you can decide why some boats can hold more weight than others. This would be a fun thing to tally-up with your younger children if you didn't want to delve too deep into the science. Then you can spend some time to find other waterproof objects and try to see if your boats can hold them and discover whose design was the strongest.
For your older kids or little scientists at home, you can take this experiment a step further by measuring the volume of each tin boat that you have made. You can do this easily by filling up your boat with the dry rice and then pouring it into the measuring cup to measure the exact volume of each boat. Then by adding as many pennies as you can, one by one before the boat sinks and spreading the weight equally, you will be able to calculate the density of the water as it will be roughly equal to the density of your boat just before it sinks.
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Kidadl provides inspiration to entertain and educate your children. We recognise that not all activities and ideas are appropriate and suitable for all children and families or in all circumstances. Our recommended activities are based on age but these are a guide. We recommend that these ideas are used as inspiration, that ideas are undertaken with appropriate adult supervision, and that each adult uses their own discretion and knowledge of their children to consider the safety and suitability.
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