1 year ago
Last edited at 11:56AM on 12/25/2012
Hammers work like force amplifiers - they convert kinetic energy -> mechanical energy and back. Because they're heavier, they're harder to move once they've been swing (law of inertia). You don't use your hands because a) it would hurt, b) your hands aren't heavy enough to drive the nail and c) hammer heads have a wider surface, making it easier to hit the target.