How Can a Locomotive Pull a Long Train That’s Much Heavier?

Have you ever watched a mile-long freight train rumble by and wondered how one locomotive can pull more than a hundred fully loaded cars? The locomotive weighs maybe 150 metric tons, and each car is ...
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Demonstrating “number of collisions = pi” in a real-world experiment suspended apparatus minimizing friction reproduces 31 collisions (3.1) at a 1:100 mass ratio

A suspended apparatus used to minimize friction during the experiment. The heavier brass cylinder and lighter ping-pong ball collide repeatedly against the transparent wall, reproducing 31 collisions ...