Item Type: ToyProduct Name: Pendulum InstrumentToy Type: Puzzle AssemblyProduct Size: Approx. 10 x 10 x 20cm / 3.9 x 3.9 x 7.9in Product Packaging Size: Approx. 13 x 24.5 x 3cm / 5.1 x 9.6 x 1.2in Product Net Weight: Approx. 61 gMaterial: WoodenDIY: YesPacking: Opp Ziplock BagAbility Development: Intellectual DevelopmentScience and Education Toy Type: Physical ClassApplicable Age: 5 Years Old Or OlderKnowledge Card: The watch test stand is a teaching experiment instrument made by the principle of pendulum inertia. Through various swinging experiments on the weight of the objects on the rope, the magnitude of the external force and the length of the rope, it is possible to visually observe the amplitude of the swing, the number of swings and the swing time of the object under the combined action of external force, gravity and inertia. The larger the external force, the longer the rope is dropped, the heavier the object, the larger the swinging amplitude of the object, the longer the swing time, and the slower the speed..w-e-text table td,.w-e-text table th,.wang-edit-text table td, .wang-edit-text table th{border: .5pt solid 000;};.w-e-text table,.wang-edit-text table{border: 1px solid 000 important;}