{"product_id":"trumpets-on-a-train-plate-089-physics-poster","title":"Trumpets on a Train – Plate 089 Physics Poster","description":"\u003cp\u003ePlate 89 speaks for itself: \u003cem\u003e“The note changed as they passed.”\u003c\/em\u003e\u003c\/p\u003e\u003ch3\u003eThe Physics\u003c\/h3\u003e\u003cp\u003eBuys Ballot put musicians on a train near Utrecht to test Doppler's prediction. Listeners heard the note sharpen as the train approached and drop once it passed.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003ef′ = f c \/ (c − v_s)\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ef′: heard frequency, Hz\u003c\/li\u003e\n\u003cli\u003ef: emitted frequency, Hz\u003c\/li\u003e\n\u003cli\u003ec: speed of sound, m s⁻¹\u003c\/li\u003e\n\u003cli\u003ev_s: source speed toward the listener, m s⁻¹\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e1845: musicians on a train near Utrecht. Sharper as it came, flatter once it passed.\u003c\/p\u003e\u003ch3\u003eSources\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eC. H. D. Buys Ballot, Ann. Phys. 142, 321 (1845).\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eOn the poster\u003c\/h3\u003e\u003cp\u003ePlate 089, “Trumpets on a Train”: the pixel-art plate with its slogan “The note changed as they passed.”, the key equation and the facts panel shown above. Pixelated Physics. Physics. Personified.\u003c\/p\u003e","brand":"Pixelated Physics","offers":[{"title":"9'' x 12\" (Vertical) \/ Matte","offer_id":50962699092071,"sku":"22048696589248499560","price":19.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Fine Art","offer_id":50962699124839,"sku":"33701193544169507673","price":29.99,"currency_code":"USD","in_stock":true},{"title":"9'' x 12\" (Vertical) \/ Semi Glossy","offer_id":50962699157607,"sku":"20834646255858680248","price":19.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Fine Art","offer_id":50962699190375,"sku":"69771676836536652319","price":44.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Semi Glossy","offer_id":50962699223143,"sku":"59228938138354282769","price":29.99,"currency_code":"USD","in_stock":true},{"title":"18″ x 24″ (Vertical) \/ Matte","offer_id":50962699255911,"sku":"18143803778020495007","price":29.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Matte","offer_id":50962699288679,"sku":"12015694995475323249","price":69.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Fine Art","offer_id":50962699321447,"sku":"10548783650321412008","price":119.99,"currency_code":"USD","in_stock":true},{"title":"36'' x 48\" (Vertical) \/ Semi Glossy","offer_id":50962699354215,"sku":"19040791857791046647","price":69.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0596\/8746\/9159\/files\/17596230139659081820_2048.jpg?v=1793734535","url":"https:\/\/pixelatedphysics.com\/it\/products\/trumpets-on-a-train-plate-089-physics-poster","provider":"Pixelated Physics","version":"1.0","type":"link"}