Harbottle Air Pressure Demonstration 

This item came to me in my Spring 2022 Curiosity Box subsciption:
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A nice glass version is available from this trusted seller:
From Educational Innovations: BUY NOW Harbottle Demonstration 

Harbottle Balloon Demo: a regular untied balloon remains inflated- one can even look down the neck of the balloon and see inside! Just blow up the balloon inside the bottle and then cork the hole in the opposite end- in so doing the inside of the balloon is experiencing the full force of air pressure, but the exterior of the balloon is protected from the crush of air pressure by the rigid wall of the bottle. Air pressure at sea level is 10.1 Newtons of force per each square centimeter of area (14.6 pounds per square inch). The bottle allows a pressure differential, pressure on the inside but much less on the outside of the balloon. The inside air pressure would lead to 12.5 pounds of force pushing outward on a 2 inch diameter balloon- more that enough to balance the elasticity of the rubber balloon material. Take the cork out and now both sides experience the same air pressure and the elastic force is no longer balanced. A fun demonstration reminding us that we live at the bottom of a deep sea of atmosphere! 

Magnetic Newtons Cradle

This magnetic version fo Newton's cradle is no longer in production, but somtimes found on ebay:
From eBay: Search NOW: Magnetic Newon's Cradle

Here are some nice versions of the classic Newton's Cradle 
and here is a nice Magnetic Replusion Demonstration

Magnetic Newton's Cradle: the famous collision demonstration reimagined with opposing magnets as the pendulum weights- shown here in two modes of operation. Initially the collision pattern looks similar to the traditional colliding spheres version but quickly goes chaotic- the magnetic field of each weight interacts with all the other magnets simultaneously making the system nonlinear. A 1990s desk toy by Fascinations- sadly no longer in production. 

Newtons Yo-Yo

Get a set here: 
From Educational Innovations: BUY NOW Newton's Yoyo 
 

Newton Yo Yo: Newton's 3rd Law states that action force equals opposite reaction force- the the green and yellow spheres have equal mass, so the forces of the collision provide accelerations that are equal and opposite such that the spheres trade places.