Physics in 5 Seconds

Every year I introduce inquiry labs and lab write-ups by giving my students a lab to do at home.  They bring in the result and present it to the class and then they write it up in their lab notebooks.  In my chemistry classes, the lab was to bake cookies without a recipe.  Now that I’m teaching physics, the lab is to make a 5-second timer out of anything they can find as long as they don’t use electricity, a clock, or human power beyond what it takes to start the timer.

So far, the lab is a tremendous success.  Tthe timers today’s class made included:

• roll a golf ball around a loop-the-loop track and off the end until it travels a specific distance (4.62 s)
• light a strip of paper of a specific size on fire and wait until the fire burns itself out (5.53 s)
• light a match and wait until it burns down to a mark at a specific point marked on the matchstick (4.41 s)
• make an “hourglass” out of two soda bottles and water (4.53 s)
• make an “hourglass” out of two soda bottles and sand (5.22 s)
• spin a quarter on the lab table and wait until it stops making any sound (4.56 s)
• make a pendulum out of a rock tied to a piece of string  and count a specific number of swings (4.72 s)
• make a pendulum out of a padlock tied to a piece of string and count a specific number of swings (8.40 s)
• roll a matchbox car down an incline (made by a binder) and across a lab table (1.09 s)
• capillary action through a tissue to a mark on the tissue (11.00 s)

I think my students probably don’t yet appreciate what they got out of doing the experiment, but I really think they learned a lot of what I was hoping for.

Tomorrow I’m doing the same thing with my other four classes–I’m eager to see what they come up with.

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