Budget physics

Micro Racer in a Glass

These micro racer cars are sold under many brand names, and most come with a clear sphere to demonstrate this centipetal accelration phyenomenon. 

From Amazon: BUY NOW: Micro Racer + Sphere

Micro Racer in a Glass: This tiny battery powered car overcomes gravity through centripetal acceleration and slight friction with the glass surface. With sufficient velocity the surface normal force supplies the centripetal acceleration. The car’s battery last for many minutes and is USB rechargeable.


In-Feed Google

Oil Drop Timer

Get one here: 
From Amazon: BUY NOW Dolphin Timer 

Oil Drop Timer with Dolphins: immiscible fluids of different densities stay separate under gravity with the lightest density on top. The density of the plastic dolphins is greater than the density of the top fluid but less than the density of the bottom fluid, so they stay at the boundary in equilibrium. The dolphins have a metal weight in their tails so that the buoyant force will keep them upright even as the liquids trade places (2 minutes shown in time-lapse). Archimedes' Principal at work here at multiple levels. 

Pixelated Playing Cards

Available from these fine sources: 
From Amazon: BUY NOW Pixel Cards 
From eBay: BUY NOW Pixel Cards

Pixelated Playing Cards: what one sees is all about the lighting with this transparent deck of cards. When backlit these poker sized cards become simply a grid of dots- reminding us that what we see not only concerns the physical properties of the perceived object, but also the location of the light source and the frequency and intensity of its emissions.


In-Feed Google 2

Mini Balance Pterosaur

Get this mini prehistoric balance beast here: 
From Amazon: BUY NOW Balance Pterosaur

Mini Balance Pterosaur: weights in the forward wing tips create a center of mass below this pterosaur's beak- making a system that can rotate and oscillate about a stable equilibrium condition. No magnets used or needed for this physics! Usually this toy is found in the form of a bird (direct dinosaur descendent). Pterosaurs are not dinosaurs, but are the largest animals to ever fly, and powered flight has only evolved four times: bats, birds, pterosaurs, and insects- in reverse order. 


Top Secret

This physics toy top is available here: 
From Educational Innovations: BUY NOW Mystery Spinning Top 

The amazing green magnetic viewing film is also available: 
From Educational Innovations: BUY NOW Magnetic Field Viewing Film 

Here is the 1974 patent showing the very simple circuit of this device. The spinning dipole (the top itself) induces a current in one of the coils, and this current is fed to the base of the transistor turning the electromagnet on when the top is near. 
 

"Top Secret": this top will stay spinning for more than a week- because it is actually a motor! The top is a dipole magnet (as revealed by Magneview film) and the base has an electromagnet that gives the dipole a push when the top comes near the center. An ingeniously simple circuit consisting of only a battery, a coil, and a transistor, is activated when the spinning magnet nears the coil turning on the electromagnet to give a boost to the spin of the magnetic top.

Hyperbolic Holes

This inexpensive kit available here: From eBay: BUY NOW
Hyperbolic Holes Kit

Hyperbolic Holes: a straight rod, in this case a pencil, glides through a symmetrical pair of curved holes. The design is based on the hyperboloid, the 3D ruled surface traced by an offset rotating diagonal line. This device is sold as an inexpensive kit to assemble yourself, and includes a motor with geared drive and pre-cut pieces. The pencil is my addition- just the right size to clear the curved openings.


MaBoRun Mini

Many styles to choose from- get a MaBoRun here: 
From Amazon: BUY NOW MaBoRun Mini Marble Run 

MaBoRun Mini IV: rolling marbles doing tricks as potential energy of gravity is converted to kinetic energy. In this mini-marble run a battery powered auger conveyor (Archimedes' Screw) brings the marbles back to the top and conservation of angular momentum produces a simulation of decaying orbits as the marbles whirl down the the main funnel shaped feature
 

Magnetic Top and Snake

Available in a variety of styles: 
From eBay: BUY NOW Magnetic Top and Snake 
From Amazon: BUY NOW Magnetic Top and Snake 

Magnetic Top and Snake: the magnetic tipped top stays on the perimeter of the steel snake (or is it a planarian?)- but since the top has much more mass, the snake moves the most slithering to and fro. This kinetic art toy has been around for decades and takes advantage of Newton's 3rd law and rotational kinetic energy. 

Mirror Illusion Motion Bank

A few of these are available on eBay as of this posting. 

From eBay: BUY NOW: Mirror Illusion Bank

Mirror Illusion Spacecraft Bank: Symmetry + Reflection = Illusion. Deposit a coin (which seems to vanish) and a spacecraft of some sort states to revolve within a silver ring seemingly suspended in space. The symmetry of the ring and craft allows a half of these objects to appear as a whole, and a AA battery powers a motor which drives gears to slowly spin the portion of the mirror inside the ring (with the spacecraft attached). The best version of the mirror illusion box I’ve seen.

 


Sprial Oil Drop Timer

Get one here:

From Amazon: BUY NOW: Oil Drop Timers

Spiral Oil Drop Timer: when this drop timer achieves its steady state the drops form with amazing regularity in terms of both the size of the drop and the spacing between drops. The physics of immiscible liquids, surface tension, viscosity, and gravity combine to produce these interesting patterns. 

 

Precession of a Gyroscope

Get one here: 
From Amazon: BUY NOW Gyroscopes 
From eBay: BUY NOW Gyroscopes 

Precession of a Gyroscope: in defiance of gravity this gyroscope is supported only at one end. The physics and vector nature of angular momentum! Note that as friction slows the rotor of the gyroscope down, the precession rotation rate gets faster and faster. After some energy loss the gyroscope contacts the table and vibrations move the unit around while the angular momentum maintains its orientation. 

Reaction Rocket

The essence of a great physics toy: simple design showing comlex physics 
From Educational Innovations: BUY NOW Reaction Rocket 

Reaction Rocket: projectile launch via momentum transfer in slow motion. The superball/straw base bounces off the table top and then immediately collides with the bottom of the rocket sending it off with a velocity slightly less than 3 times the velocity of the rising ball (true if the ball is more than three times the mass of the rocket). Newton's third law in action! Note that the rocket rises much higher than the drop height (up to 9 times higher).