Car Safety and Stopping Distances – year 10
Potholes are a serious safety concern: they can damage vehicles directly, but they also affect their stopping distances. This can contribute to accidents. This worksheet applies students’ knowledge of the ’suvat’ equations to consider vehicle braking distances.
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Tag Archive for: dynamics
Big Mouth Tumblewings
Big Mouth Tumblewings
When the Wright Brothers, Wilbur and Orville, first set out to build a successful aeroplane, they were mocked. People believed it couldn’t be done and, even if it could, there would be no commercial use! The brothers proved their doubters wrong: on the 17th December 1903 they made two successful (if rather short) flights in a powered aeroplane, controlled by a pilot. If you want to find out a little more about the history of flight, have a look at the gallery below. Now it’s your turn to defy convention by building and flying a Big Mouthed Tumblewing, a flying craft unlike any you’ve seen before. Tumblewings are very light spinning shapes that glide – surf, almost – on an updraft of air. There are many designs, but we particularly like this one, designed by Slater Harrison over at the excellent sciencetoymaker.org. Check out this video for tips on making and flying your own.
They’re easy to make, but keeping them airborne is a knack that takes practice. You’ll need open space indoors and lots of perseverance. The film will help you spot the things you’re doing right and wrong.
If you would like to make your own, we have:
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Tumblewing template (PDF, 1Mb).
Make sure you print full size! - Tumblewing instructions (PDF, 2Mb).
We’ll update this page with a flying training film once we’ve made one we’re happy with – in the meantime, do watch the video above. It’ll help explain what’s going on, and more importantly how to do it yourself.
Our thanks to Slater Harrison for sharing his brilliantly simple tumblewing design with us. Do visit his site!
How (tumble)wings work
Tumblewings are unusual, as wings go. If you look at an aeroplane, you’ll immediately notice one key difference: their wings don’t spin. The same is true of birds, which is probably good for gannets or they’d get terribly dizzy. Helicopter wings do spin, but think about it a little and you’ll notice that they’re not spinning in the same sort of way.
So: Tumblewings. Their spin helps keep them stable, but it also makes them slide forwards through the air as they fall. Walking behind them with a board generates an updraft of air, balancing that fall. Sometimes you’ll see birds – like that happily-not-dizzy gannet – soaring on the updraft at a cliff or hill. They’re doing the same sort of thing, but much more efficiently.
Birds and aeroplanes can glide further than tumblewings because they’re much more efficient wings. Explaining how wings generate lift is a famously subtle challenge. Here’s an animation from Derek Muller of Veritasium, which is about as good as anything we’ve seen.
History of Flight Gallery
When you look at the gliders and aeroplanes the Wright Brothers made, sometimes they don’t look much more advanced than the tumblewing – just a few bits of canvas held apart by some sticks. Perhaps a bit more than a weekend project?
Vacuum Bazooka (shooting sprouts, just to be festive)
Stuff flying through the air is always fun. Unless you’re the owner of the priceless vase which happens to be in the way of the otherwise-graceful arc, but that’s obviously not going to happen to you, right? You’re more careful about aiming. Ahem.
Even better is making things you really really don’t like sail through the air with the greatest of east. Above, TV presenter Greg Foot dons his best festive jumper and uses a vacuum clear to hurl his hated brussels sprouts as far as possible. This sort of vacuum bazooka is a classic thing to make, and while it can be a bit fiddly it’s well worth having a go if you’re feeling bored over Christmas.
If you’re really ambitious, you might end up completely obsessed with the things, like our chum Dave Ansell:
Or, if you fancy something a bit simpler, our partners the Centre for Life have a not-quite-the-same-but-similar-results demonstration:
Merry Christmas. And do try not to put anyone’s eye out with flying objects.
Rubber Band Cannons
An easy make & do with household scrap and elastic bands, from the Royal Institution’s excellent ExpeRimental series. These are all straightforward activities using household materials, perfect for families to collaborate or compete over on a rainy day.
This film shows you how to turn crisp tubes and a small pop bottle into a surprisingly powerful (and entertainingly inaccurate) foil-firing cannon. Along the way there’s plenty of opportunity to discuss energy transfer and projectile dynamics… or simply to knock things over and cause widespread mayhem.
