One push, one catch — Newton's cradle shows momentum and energy transfer

A wooden frame and five balls on strings: lift one and release — matching balls swing out on the other side while the middle ones barely move. That classic demo is this wooden Newton's cradle DIY: hands-on momentum and energy conservation for a desk-top physics STEM kit.

Great for science warm-ups, STEM corners, and parent–child “observe then explain” time. No motor or battery — the learning is in watching, describing, and trying again. Suggested age 7+; adult help for string and small parts. Not marketed as ages 3–6.

Who is it for? Age & STEM skills

Ages 7+. Ideal for first mechanics concepts and quiet desk experiments — not a light-up electronic toy.

• Science exploration — momentum, energy transfer, collisions
• Observation — count balls lifted vs balls that swing out
• Making — assemble the wooden frame and hang the balls
• Communication — explain why the middle balls seem still

How to build & play

1. Inventory parts against the list (as shipped).
2. Assemble the wooden frame so it sits stable.
3. Hang ~five balls; adjust string length so they align.
4. Basic test: lift the outer ball gently; watch the opposite side.
5. Compare: lift two or three; or push from both ends.
6. Discuss: where did the energy go?

In the box

• Wooden frame parts
• Strings and about five cradle balls (clear / pearlescent look as shipped)
• Hardware if included
• Instruction guide (language as shipped)

Parent FAQ

Q: Batteries? Magnetic levitation?
A: No batteries. Non-electric hanging-ball cradle — not a magnetic-levitation variant.

Q: What age?
A: 7+. Small parts / strings — not for under 3; not positioned as ages 3–6.

Q: What physics?
A: Intuitive momentum transfer and energy conservation through collisions.

Q: Ball material / size?
A: Photos show clear or pearlescent balls; ~15×14.6×10.8 cm class size — confirm on sample.

Safety tips

• Ages 7+; adult supervision for assembly and stringing.
• Small parts — choking hazard; not for children under 3.
• Non-electric; not a magnetic float cradle; do not modify with power or strong magnets.
• Do not swing hard enough to break the frame; keep parts out of mouths; store stably.

A lasting desk physics kit — build it, then keep exploring.