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Category Archives: What’s the Problem?

What’s the Problem?: Pepper Water

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Act 1: Observations and Hook

Water, pepper, dish soap.

Act 2: Questions, Possibilities, Resources

  • What happened?
  • How does the pepper behave differently at the start, at the end?
  • Why does it swirl around?
  • Where does pepper come from?
  • Does it work with something other than pepper? other than water? other than dish soap?
  • What is soap? What is it designed to do?
  • What does “clean” mean?

Act 3: Resolution and Continuation

  • Here‘s a pretty good explanation of how it works.
  • Would it work again/faster/better if soap was added a second time?
  • What if soap was added in two places at the same time?
  • How’s the pepper/water experiment similar to this? Are they related?

What’s The Problem?: Fortune Fish

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Act 1: Observations and Hook
Have you seen these before?

The writing didn’t focus well. It reads:
Place Fish in palm of hand and its movements will indicate
Moving Head … Jealousy
Moving Tail … Indifference
Moving Head and Tail … In Love
Curling Sides … Fickle
Turns Over … False
Motionless … Dead One
Curls Up Entirely … Passionate


Act 2: Questions, Possibilities, Resources

  • What happened?
  • Why?
  • What’s the fish made of?
  • Does it have to be red?
  • What might make it curl versus merely move?
  • Here’s what happens when hands are rubbed together first:
  • Here’s what happens when the fish is placed on the forearm instead of the palm:
  • Here’s what happens when hand lotion is applied first:

Act 3: Resolution and Continuation

  • What might happen if a person iced their hand before holding the fish?
  • How would a person get a fortune of “dead one” or “passionate”?
  • Will it work if you dunk it in a fish tank?
  • Will it work if you put it on a heating pad?
  • Will it work on any part of your dog?
  • What other situations would the fish work?
  • If you stack two, will one or both or neither work?
  • So, what does the fish indicate?
  • Steve Spangler details how the fish works here.

What’s The Problem?: Tides

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Holy cow, what a year so far. Now that the MTBoS challenges are (sadly!) at an end, I figure I should get back to posting things of my own volition. And so, here’s another WTP? post (can I use that? Looks kinda weird. I’ll think on it).



Act 1: Observations and Hook

I use this web applet in physics. I don’t know how to get it into my webspace, so I’ll just provide this link: Press play. Step through with >> and << . The legend makes it look a little confusing, but once you decipher the picture, cover up the legend with a Post-It note or something. Also, this link seems to move every year or two, so I might update it if need be.

Act 2: Questions, Possibilites, Resources

  • Why is the sun so small?
  • Why doesn’t the moon turn?
  • What continents are showing?
  • Is this to scale?
  • Is there zero water when the blue blobby-thing disappears?
  • Why are Spring tides so much higher than Neap tides?
  • Why are there high tides on both sides of the planet if the sun and moon are one side?

Act 3: Resolution and Continuation

  • The applet is definitely not to scale. The moon actually is turning, but it’s tidally-locked with the Earth.
  • This is supposed to be a roughly North-Pole view of the Earth.(How would you have to redesign the applet if this were an Equator-centric view?)
  • Besides the oceans, what bodies of water have tides? What’s the limit as to size? Can people have bodily-tides?
  • Do tides affect only water?
  • To be a more accurate representation of this part of the solar system, what would you add/change?
  • What would have to happen for tides to be non-existent? Twice as big?
  • Are tides changing over millennia?
  • Mars has two (relatively small) moons. If Mars had liquid water, what might its tides look like?
  • Make a model for the theoretical tides on other moons.

What’s the Problem?: Air Cannon

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While the school year ramps up, I’ll try to post a couple things I’ve used in class in the past. In the upper Midwest (mostly), there’s a chain of sandwich shops called Erbert and Gerbert’s. In part because of how late they delivered, a lot of my limited-college-money was given to them, quite happily, in exchange for soup or submarine-themed-subs. The best part is that they pinch out the squishy middle part of the bread to make room for fillings, and give you the “guts” alongside your main meal. Now I’m hungry.

Anyway.

E&G is also known for their somewhat strange commercials. Besides having a pig as a mascot, their commercials were usually pretty (wonderfully) strange. Take this one, for example.


Act 1: Observations and Hook

I use this video during Newton’s Laws of Motion. It could also be used for some other mechanics-related topics.

Act 2: Questions, Possibilities, Resources

  • What the what??
  • Where do you see Newton’s Laws in the video?
  • Would the air cannon still work without the fog/smoke stuff?
  • If you make the shape of the output hole square, what will the vortex look like?
  • What does inertia have to do with how the smoke ring forms?
  • List basic parts (or draw a schematic) of air cannon parts.
  • How does the length of the barrel affect the speed of the vortex?
  • Why does the size of the vortex grow as it travels?
  • What would you change in the cannon to get a slower-moving ring?
  • How does air have enough force to knock things over?
  • What if you put confetti inside?

Act 3: Resolution and Continuation

  • It’s pretty easy to make your own air cannon. The second link actually has a number of answers for Act 2.
  • Propose your own air cannon design using a cardboard box and any other materials.
  • Would a similar-sized cardboard version of the video air cannon have the same power/speed/force?

In case you love this video as much as I do, here’s the behind the scenes video of how they made the air cannon (plus a flash of math, a quick conversation with a physicist, and some sandwiches).

What’s the Problem?: Hourglasses

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A la Dan Meyer‘s Three-Act Tasks, I’d like to try a few science-related ones. I think a lot of Mr. Meyer’s scenarios could be science-y, but in the context of math class, they’re math-y. Actually, his method for creating the Task is pretty close to Scientific Method, i.e., observe a Thing, wonder, test. Booya! science for the WIN!

Ahem.

Maybe this is just a version of discrepant events. This particular one isn’t terribly discrepant, but maybe it’s a little strange. Here’s the first (I hope) of a series I’m going to call, “What’s the Problem?”


Act 1: Observations and Hook

There are a lot of possible questions here. It’s almost toward a 101qs-type thing instead of a particular task.

Act 2: Questions, Possibilities, Resources
image

  1. List all of the parts seen in the video. List other characteristics of the hourglasses.
  2. Why so many hourglasses?
  3. How long do they run?
  4. Are they supposed to be the same time length?
  5. Is the one with the most sand the longest?
  6. Does the sand fall at the same rate for each hourglass?
  • Hourglasses each have a clear barrel, black end-caps, and some amount of sand. Characteristics that might differ include the width of the barrel, the width of the narrow opening between top and bottom.
  • There’s a board game that came with these ten hourglasses.
  • They vary in timing-duration from 25 seconds to 1:07 minutes, according to my stopwatch.
  • They are all supposed to be one minute timers.
  • The one with the most sand is not the longest timer-length (it runs about 1 minute) The one with the least amount of sand, however, is the shortest.
  • Sand does not appear to fall at the same rate (the shortest duration hourglass appears to pile up more quickly than the rest).

Act 3: Resolution and Continuation

In order, the duration of the hourglasses looks something like this:

hourglasses in order of duration

0:25, 0:50, 1:00 (x3), 1:01, 1:02, 1:04 (x2), 1:07
Note: that the amount of sand does not appear to increase consistently as duration increases


  • Only three of the ten hourglasses actually run for one minute (although two others run 1:01 and 1:02).
  • How might this potentially affect game play for the board game?
  • Why doesn’t the amount of sand seem to matter for duration (i.e., other factors in falling sand)?
  • Could we make them all into the one-minute timers with current materials?
  • If we could open all of the timers and make them equal duration, what would that time be?
  • How might these hourglasses have been made in the first place, since they are not terribly accurate?
  • Would weighing them help?
  • How would a different grit of sand help or hurt?
  • Would a different color of sand help the stopwatch-holder (and board-game-player) see the endpoints better?