{"product_id":"katers-reversible-pendulum-plate-001-physics-poster","title":"Kater's Reversible Pendulum – Plate 001 Physics Poster","description":"\u003cp\u003ePlate 1 speaks for itself: \u003cem\u003e“Flip it. Same beat. That's g.”\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eA compound pendulum with two knife-edges swings with the same period about either edge only when the edge separation equals the length of the equivalent simple pendulum. Kater used this to measure g without needing the centre of mass or the moment of inertia.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eg = 4π² (h₁ + h₂) \/ T²   (when T₁ = T₂ = T)\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eg: local gravitational acceleration, m s⁻²\u003c\/li\u003e\n\u003cli\u003eh₁, h₂: distances from the centre of mass to each knife-edge, m\u003c\/li\u003e\n\u003cli\u003eT: common period about either edge, s\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhen both edges beat alike, the gap is the length. London, 1817–18: standard g = 9.80665 m s⁻² gives T ≈ 2.006 s for a 1 m equivalent length.\u003c\/p\u003e\u003ch3\u003eSources\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eH. Kater, Phil. Trans. R. Soc. 108, 33 (1818).\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eOn the poster\u003c\/h3\u003e\u003cp\u003ePlate 001, “Kater's Reversible Pendulum”: the pixel-art plate with its slogan “Flip it. Same beat. That's g.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.\u003c\/p\u003e","brand":"Printify","offers":[{"title":"9'' x 12\" (Vertical) \/ Matte","offer_id":50961376968807,"sku":"13931064719092885635","price":19.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Fine Art","offer_id":50961377001575,"sku":"11614947687730671058","price":29.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Semi Glossy","offer_id":50961377034343,"sku":"16957450268007601562","price":19.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Fine Art","offer_id":50961377067111,"sku":"28503964909385209330","price":44.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Semi Glossy","offer_id":50961377099879,"sku":"24642524164330428866","price":29.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Matte","offer_id":50961377132647,"sku":"27846245702327807044","price":29.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Matte","offer_id":50961377165415,"sku":"14092175399415874252","price":69.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Fine Art","offer_id":50961377198183,"sku":"56045118614905085084","price":119.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Semi Glossy","offer_id":50961377230951,"sku":"28726449451145510349","price":69.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/458684635292019623_2048.jpg?v=1793728202","url":"https:\/\/pixelatedphysics.com\/nl\/products\/katers-reversible-pendulum-plate-001-physics-poster","provider":"Pixelated Physics","version":"1.0","type":"link"}