Today we explored the effect that altering time for an object to accelerate has on the measured value of acceleration, the force involved, and the damage that results when time to accelerate is shortened.
We analyzed time for an object to move from 20 m/s to a stop in two situations: one where the object stopped in 0.02 seconds, and another where the object stopped in 0.5 seconds. Accelerations were 1000 m/s^2 vs 40 m/s^2, and the forces (assuming a 2kg object) were 2000N vs. 80N.
We discussed the importance of time to accelerate and relation to design in helmets, playgrounds, and cars: if your head hits the pavement and your brain accelerates to a stop in 1mm versus hitting a softer surface and accelerates over 1cm (10x farther), the time for impact will be 10X longer and the force experienced will be 10X less.
We demonstrated this idea by trying to throw eggs into a loose sheet. Very few were broken, most likely due to other causes, and the school was accidentally targeted by a few off-aim students. Luckily it was outside!
Tuesday and Wednesday we'll be exploring the concept of friction and learning about some new tools to measure (scales)
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