"No problem," thought the monkey, "I will just watch the rifle. When I see the flash from the muzzle, I will immediately let go of the branch and fall out of the bullet's way."
Is the monkey right?
In the lecture demonstration a few substitutions are made:
|Tree Branch||Iron rod|
|Muzzle flash||Thin wire cut by bullet|
|Gun powder||Puff of hot air|
A metal can is substituted for the monkey for simianitarian reasons.
The can is held up by an electromagnet on a high rod. An instructor across
the room aims a blowgun (a pipe) at the can by sighting down the hole. He or she
also shines a laser pointer down the pipe to show that it is aimed at the can.
A metal slug is inserted into the pipe to act as the bullet.
The instructor shoots the bullet by blowing into the pipe. As the bullet leaves the end of the blowgun it breaks a thin wire which was placed across the end of the pipe. The wire was in the electromagnet's circuit and in breaking it stops the current flowing through the electromagnet. Thus the magnetic force ceases and the can starts to drop just as the bullet leaves the blowgun.
Will the can fall out of the bullet's way?