AMAZING Physics | 7 Tricks That You Must See
1 – Mould effect
It’s obvious that the weight of the heavy falling beads is pulling the remaining beads from the pot. However, it’s not so obvious whats causing the large arc and why the beads don’t just slide directly over the edge of the pot. It’s said that you should view the chain as a series of short ridged rods rather than a flexible string of isolated beads. When the beads are pulled out of the pot by the weight of the falling beads it causes the ridged rods not only to be lifted but also to rotate. The combination of these two forces causes the end that is not being picked up to push down on the pot which in turn creates a kick. It’s this kick that sort of pushes the beads up out of the jar while they are also being pulled down from the other-side and thus the arc is formed.
2 – Cool pressure trick
Heating air causes it to expand and cooling it causes it to contract. The boiling water in the bottle causes the glass to get very hot so the air inside the glass also gets hot causing it to expand. When the bottle is put into the cold water it quickly cools causing the air inside to contract rapidly which creates a vacuum and sucks the water up.
3 – The lenz effect
“Lenz’s law states that the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to oppose the change in flux and to exert a mechanical force opposing the motion.” When the magnet is dropped into the conductive alloy pipe it causes a change in magnetic flux. This change in magnetic flux creates a current in the Aluminium pipe which opposes the change and slows the magnet down in order to reduce the change in flux.
4 – Anti-gravity water trick
There are a couple of forces at work here, air pressure and surface tension. The atmospheric pressure all around us helps to hold the plastic in place. In addition to this, there is a small pocket of air at the top of the bottle. Because no more air can get to this pocket an area of low pressure is formed. A combination of low air pressure inside the glass and higher air pressure outside of it help to keep the plastic in place. Next is surface tension and adhesion. Water molecules are attracted to each-other like little tiny magnets with a positive and negative end. On the surface of the water, the molecules are able to get closer to each-other than below the surface, this creates a sort of elastic surface layer. Adhesion occurs because of the water molecules positive and negative ends are not only attracted to each-other, but also to other materials such as the plastic circle in this experiment. This causes the water molecules to adhere to the plastic whilst maintaining the surface tension with the other water molecules. It is a combination of all these factors that keep the plastic in place and stop the water gushing out. Check out this post for a more detailed explanation.
5 – Water on a string surface tension trick
This trick works on the same surface tension and adhesion principles as the one above
6 – Ring catch chain trick
The trick with this one is in how you drop the ring. If you let go of the ring with both fingers at the same time it would just drop to the floor. What you need to do is just release your thumb and keep your finger still. When you do this it causes the ring to fall at an angle which in-turn causes the chain to loop itself over the ring and get caught.
7 – Fork and spoon center of gravity trick
Every object has a center of gravity. This is the central point at which gravity acts upon the object. When you position a fork, spoon and tooth pick in this way, the center of gravity or the pivot point happens to be completely central and towards the far end of the tooth pick which just looks so wrong. It looks even more impressive when you burn the toothpick at both ends, this has no effect on the center of gravity so everything remains balanced. The reason the toothpick does not continue to burn past the metal of the fork or the glass is that when it reaches these points its robbed of its heat and goes out.