hammer, PVC, movable hammer block
rubber mallet, two potatoes, knife

 

Code Number: 1F20.60

Demo Title: Tighten a Hammer Head - Knife & Potato

Condition: Excellent

Principle: Inertia of Mass

Area of Study: Mechanics

Equipment: 

Hammer, PVC and movable hammer head, large knife, large potato.

Procedure:

This demo is used to show that you don't tighten a hammer head by hitting it onto the handle, but rather by placing the head on the handle and then slamming the other end of the handle onto the table.  Doing this with the PVC and movable hammer head will show that the hammer head travels downward onto the handle.  If you try to pound the hammer head onto the PVC handle, the hammer head will actually move off the handle.

You can also do this with a potato and long knife.  Stab the potato with the knife, and then holding the system vertically, hit the end of the knife handle with the hammer and watch the potato "climb" the knife blade.

References:

  • Tatiana Erukhimova, "2024 David Halliday and Robert Resnick Award for Excellence in Undergraduate Physics Teaching Lecture: It's Not Business, It's Personal.  Teaching Large Classes, One Student at a Time.", AJP, Vol. 92, #12, Dec. 2024, p. 910.
  • Martin Gardner, "Dividing An Apple", Entertaining Science Experiments with Everyday Objects, p. 127.
  • Tom Senior, "The Loose Hammer-Head Extended", PIRA News, Vol.20, # 1, p. 10.
1F20.60 -Tighten a Hammer Head
Knife and Potato - 1F20.60