A popular demonstration involves a ruler resting flat on the table with half of its length out of the table’s edge. A newspaper is laid flat on top of the ruler. The demonstrator first slowly lifts the newspaper using the ruler and shows the crowd that the ruler is strong enough to lift the newspaper without breaking. The setup is repeated once more but this time the demonstrator strikes with great speed the part of the ruler that is outside the edge of the table, breaking the ruler in the process. How does this happen?

A popular demonstration involves a ruler resting flat on the table with half of its length out of the table’s edge. A newspaper is laid flat on top of the ruler. The demonstrator first slowly lifts the newspaper using the ruler and shows the crowd that the ruler is strong enough to lift the newspaper without breaking. The setup is repeated once more but this time the demonstrator strikes with great speed the part of the ruler that is outside the edge of the table, breaking the ruler in the process. How does this happen?

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