With the help of a simple manual vacuum pump that is used to keep food fresh, we can demonstrate the effect of a reduced pressure on the boiling point of water. This leads students to a discussion on what it takes to boil a liquid and a deeper understanding of the kinetic model of matter.
In a previous demonstration, we put a boiled egg into a flask with a mouth narrower than the egg. The challenge is now to remove the egg from the flask without breaking it. Materials Flask Egg Water Bunsen burner or candle Procedure Pour some water into the conical flask. Invert the flask quickly over a
This classic physics demonstration is used to show the effects of pressure difference between the atmosphere and a cooling volume of air. With a set of clean apparatus, you can even have the egg for a snack after that. Materials Hard-boiled Egg Flask or glass bottle with mouth smaller than the egg Paper measuring about
[accordions autoHeight='true'] [accordion title="1. Definitions"] The magnetic flux density at a point is defined as the force acting per unit current per unit length of the conductor when the conductor is placed at right angles to the field. One tesla is the uniform magnetic flux density which, acting normally to a long straight wire carrying
This demonstration requires no material other than your own fingers. Hold your index and middle fingers close to each other, leaving a small slit between them about 1 mm in width. Look through the slit into a source of light such as the window or a lamp. You will need to look with one eye up