Ð î ç ä ³ ë 3. ÂÇÀªÌÎÄ²ß Ò²Ë. ÑÈËÀ
Ìàë. 3.87
ÿêùî íàëèòè â íèõ ð³äèíè ð³çíî¿ ãóñòèíè (ρ1 ³ ρ2), ÿê³ íå çì³øóþòüñÿ ì³æ ñîáîþ? Öå ìîæå áóòè, íàïðèêëàä, ìàøèííå ìàñòèëî ³ âîäà. Îáèäâ³ ð³äèíè çàëèøàòèìóòüñÿ â ñòàí³ ñïîêîþ (ïåðåáóâàòèìóòü ó ð³âíîâàç³) äîòè, ïîêè ñèëà òèñêó íà âîäó ç áîêó ìàñòèëà F1 äîð³âíþâàòèìå ñèë³ òèñêó F2, ÿêó ÷èíèòü âîäà íà ìàñòèëî F1 = F2 (ìàë. 3.87). Âèçíà÷èìî ö³ ñèëè: F1 = p1S = ρ1gh1, F2 = p2S = = ρ2gh2, ρ1gh1 = ρ2gh2. Âèêîíàâøè ïåðåòâîðåííÿ, îäåðæèìî h1 ρ2 . = h2 ρ1
ßêùî â ñïîëó÷åí³ ïîñóäèíè íàëèòè ð³äèíè ð³çíî¿ ãóñòèíè, òî âèñîòè ñòîâï÷èê³â öèõ ð³äèí ó êîæí³é ³ç ïîñóäèí îáåðíåíî ïðîïîðö³éí³ äî ¿õ ãóñòèí çà óìîâè, ùî òèñêè íàä ïîâåðõíÿìè ð³äèí ó ïîñóäèíàõ îäíàêîâ³.
ÇÀÏÈÒÀÍÍß ÒÀ ÇÀÂÄÀÍÍß 1. ßê³ ïîñóäèíè íàçèâàþòüñÿ ñïîëó÷åíèìè? 2. Íàâåä³òü ïðèêëàäè ñïîëó÷åíèõ ïîñóäèí. 3. ßê ðîçì³ùóþòüñÿ â³ëüí³ ïîâåðõí³ îäíîð³äíî¿ ð³äèíè â ñïîëó÷åíèõ ïîñóäèíàõ? 4. ßê ðîçì³ùóþòüñÿ â³ëüí³ ïîâåðõí³ ð³çíîð³äíèõ ð³äèí ó ñïîëó÷åíèõ ïîñóäèíàõ? 5. ×è ñïðàâäæóºòüñÿ çàêîí ñïîëó÷åíèõ ïîñóäèí ó íåâàãîìîñò³? 6. Ó ë³âå êîë³íî ñïîëó÷åíèõ ïîñóäèí íàëèòî âîäó, ó ïðàâå — ãàñ. Âèñîòà ñòîâïà ãàñó 20 ñì. Íà ñê³ëüêè ð³âåíü âîäè â ë³âîìó êîë³í³ íèæ÷èé, í³æ âåðõí³é ð³âåíü ãàñó ó ïðàâîìó?
§ 42. ÇÀÑÒÎÑÓÂÀÍÍß ÑÏÎËÓ×ÅÍÈÕ ÏÎÑÓÄÈÍ Â ÒÅÕͲֲ Ïðèêëàäàìè ñïîëó÷åíèõ ïîñóäèí, ÿêèìè ìè ÷àñòî êîðèñòóºìîñÿ, º ÷àéíèê, ñàäîâà ë³éêà òà ³í. Ó íîñèêó ÷àéíèêà ³ â ñàìîìó ÷àéíèêó ð³âåíü âîäè îäíàêîâèé. Òîìó, íàõèëèâøè ÷àé-
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