Northwestern Physics Demos                                 Go back to Mechanics
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DCS# 4B60.18NWU# M-127    location:  3 A 5
title: Smashing Spheres
aka: burning holes in paper with KE.

Two large steel spheres are smashed together onto a piece of paper.   With sufficient kinetic energy, the thermal energy produced is sufficient to burn a hole in the paper, evident by the odor produced as well as the charred hole left behind.
  A good demo to pass around the class.

  Where does the heat to burn the paper come from?  Why does it not work if the speed is too low?
image of disk