Recently Veritasium presented this video with 5 fun physics experiments and asked us to explain them. Now he explains then in the video from above.
1. Cereals will stick to a magnet. This is not because cereals have iron atoms in them.
2. If you put any small objects over water they will follow a magnet.
It is because the water is a diamagnetic molecule and in the presence of a magnet behaves like a small magnet that repels your magnet. Thus it will create a small hole in the water and the objects will fall in it.
3. The center of mass of a stick or cane can be found just by moving your fingers under it until you get them close together.
This is because the finger closer to the center of mass carries more of the stick’s mass and thus the friction force is bigger in there. When the other finger closes in on the center of mass it will experience the same friction force as the former finger and both fingers will be able to move together.
4. Flipping the phone end over end there is not way to do it without making it also spin in other axis too. This happens because the intermediate axis is between the longest and shortest axis that have the most or the least inertia. due to this intermediate state the phone will never be able to spin only o that intermediate axis.
5. An electrically charged object can deflect a stream o water.
This is due to the fact that the water has ions, negative ions HO- and positive H+ and when you get close with an electrically (-) charged cup, the negative ions are moving back into the tap and the positive ones attact the water stream to the cup.