年級

問題的種類

自然科學
大學

力學 救救我 謝謝!(第三題不用)

1. Considerathin rod ofuniform linear mass density pL with mass 4/ and length /, find the gravitational potential。dp/有)。at a perpendicular distance Afrom the center ofthe rod. You may find the integral in (E.6) in Appendix E useful 2. A spherical planet of radius 人> consists ofacore of radius 有/ with uniform density pi. and a thick outer cloud of dust with umiform density p: Find the force (magnitude and direction) onamass箇inside the dust cloud ata position ARp from the planetcenter( 吃<訪<記), 3. Use Fermat's principle by applying calculus of variation to minimize the time oflight passing from medium ofrefractive index jg, to another medium ofrefractive index >, derive the Snells law ofrefraction: js光 名2s 銷 4. Consider the Atwood machine oftwo masses connected by amassless string oflength 7overapulley ofradius gas shown, (a) Write down the total kinetic energy and potential energy in terms of the coordinatex Hence obtain the Lagrangian ofthe system. (b) Derive the Lagrange's equation of motion and hence find the acceleration ofthe masses. x 和二 工
生物
高中

B和C選項(需要解釋) 謝謝🙏🏻

(0) 19 從適應和演化的角度來看,養雞場平時不宜在雞隻飼料中添加抗生素的最主要原因為下 “和烈哪二項# [任對才39 【95. 學測】 公會增加雞隻飼養的成本 (人偷加束難隻對抗生素產生抗藥性00會加速有抗藥性病原 體的發生_戰會讓病原體滅絕,減少地球的生物多樣性~農避免讓人吃到抗生素,因有 些人會對抗生素過纖% 八也介多放大和例作优 0
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