In a famous physics demonstration, the professor lies down with a cinder block on her chest. Her assistant then slams the cinder block with a sledgehammer as hard as he can. Although the professor would be severely injured if she received the seldgehammeer’s blow directly, with the cinder block in place she emerges from the ordeal relatively unharmed. Why? Shouldn’t having extra weight on her increase the danger rather than mitigate it?
Sometimes this demonstration involves a bed of nails, just for extra showiness.
July 15, 2009 at 4:21 am
The force is distributed over a greater area thus reducing pressure per unit area. Whereas if the professor was hit with the sledgehammer without a buffer, the pressure would be much greater over the more limited area of contact.
July 16, 2009 at 1:53 pm
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