$16.00 incl GST & delivery
A latex glove, dry fillers and reduced air pressure deliver this amazing and thought-provoking demonstration. Insert the vacuum valve in the glove, fill with one cup of sand or seeds, tie it up and suck air from it with the pump. Now pull and stretch the fingers and amazingly they get locked into position . . . Re-do it with coarser fillers such as lentils, mustard seeds, coarse polenta, etc. to see grizzly, textured skin effects on the glove. Be warned! As the air seeps back, the hand generates peculiar, life-like sounds and movements.
Why does this happen? What does it teach about atmospheric pressure?
This kit is a great teaching aid as well as a great conversation starter about our atmosphere and its invisible fast-moving gas particles.
Warning: If anyone in your audience is latex intolerant, please ensure they do not get in contact with the gloves.
Suggested Classroom Activities
1. Determine if air has mass
Use a sensitive electronic balance (~0.01g) to determine the mass of the extracted air. The glove is weighed before and after air is extracted.
When the glove gets filled with 1 cup of “whole wheat” the density is such that it just floats in water. Extracting the air, makes it sink.
3. Is it really the outside air that locks the sand in?
Extract air from the glove, extend the fingers, and place it inside a vacuum container. See photo. Evacuate the air from the container and keep your eyes on the glove . . . Then let the air flow back into the container.
What is in the kit?
Supplies so you can prepare 10 hands, 2 at a time
2 Vacuum valves
1 Vacuum pump
10 Latex gloves
1 Instruction sheet
1 cup of polenta, raw sugar or sand per hand
We have selected strong latex gloves, but you may have supplies in the lab that will do the job. Vinyl or nitrile gloves cannot be used as they do not contract well.
Selecting a filler medium:
The following two products,
Polenta (coarse) and
perform very well in this demonstration. Do not mix them, use each on its own. They have the right consistency and particle size distribution that enhance the feel. Try to locate them and use them instead of sand. You’ll need at least 1 cup.
Create a weird skin effect
Fill the gloves with any of these fillers to create a peculiar skin effect. We have used the following coarse fillers with great success. What have you got in the pantry? Tip: Do not use fine products where small particles can sneak through the fabric and block the valve. Cornflour and castor sugar is definitely out.
All material Copyright, 2019 EduScience Pty Ltd
Pack of 24 boxes, Pack of 12 boxes