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物理 高中

這個有答案但是我看不懂 求解謝謝🙏🙏🙏

示皇冠並非純金製成。」阿基米德將這個發現寫在他的著作浮體裡,並 更進一步詳述浮力理論:物體在流體中所受的浮力,等於物體所留意。 體重量,而流體的重量=(流體密度X流體體積)Xg="g,任人格 發現稱為阿基米德原理(Archinedes principle)。物體在液體中所測得的 事 重量,稱為物體在液體中的視重(apparent weight),所以沒體的視重 跟助到發作。 1 -=90 例题7-2 密度為19.3 g/cm、質量1,000g的純金皇冠,在《中所得的視重是多少,如果 金真劍合全所製成同樣質量的皇冠,在水中所得的祝重為940 gw,则会和所占比例 約為多少?(钢的密度為8.96 g/cm) 4:1 解答:(1)設純金皇冠的體積為厂,金的密度為pi = 19.3(gcm),水的密度為: - 1(g/cm),由密度公式:p=*=m = p",並利用阿基米德原理。 純金皇冠的视重=純金皇冠的實重一純金皇冠在水中的浮力 = mg – B=PiVg -p2Vg =Vg (P1-P2) P2 = piVg (1 - poza Pi 因為純金皇冠的質量m = pi/= 1.000(g),而重量= p's = 1.00 (gw),代入式,可得純金皇冠的祝重= 1.000×(1- 193 (gw)。 (2)視重=實重-浮力=940 = 1.000 - B=B= 60,根據阿基米德原理、 此皇冠體積為60 cm。 設合金皇冠含純金質量刑克,含銅質量(1.000 -)克、百度公式: 1,000 - m ,則: = 60==800(s)。 19.3 8.96 所以銅約為200(g),金和銅所占比例約為4:1。 頭題2 密度為1.5 g/cm)、質量 15g的石頭,在水中所科得石项的说重是多少? 根 : B=1000-940=60.gw 14.3 8.96 1913 i "B = L V 0 » M4 - 800g 水 ³60=xV man - 2009 W=W-B, V = 60cm is 1000-50 銷 =950gw m m m + P= == ma 1000 me 60 - =-|-- 1000 1-41

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物理 高中

21題 教教我QAQ

Section 11.3 Angular Momentum J-s behind rmv a he ur 265 = ? a ter 30. Example 11.1: A 58.1 Iw COMP string and whirled at 18. Express the units of angular momentum (a) using only the funda- momentum of magr mental units kilogram, meter, and second; (b) in a form involving the circular path. Fir newtons; (c) in a form involving joules. marw horizontal and (b) the 19. Use data from Appendix E to make an order-of-magnitude esti- 31. Example 11.2. A stai mate for the angular momentum of our Solar System about the Max 27 the end of its lifetime galactic center. mu = 17.293 of radius 4.96 X 10' 20. A gymnast of rotational inertia 63 kg•m? is tumbling head over heels dwarf of radius 4.21 with angular momentum 460 kg•m?/s. What's her angular speed? 17.99 acted on the core, fine A 660-g hoop 95 cm in diameter is rotating at 170 rpm about its 32. Example 11.2: Astro 22. A 1.3-th-diameter golf ball has mass 45 g and is spinning at central axis. What's its angular momentum? L: 1W=0-66*(0-95) x 140x277.10 km and determin core that collapsed to 3000 rpm. Treating the golf ball as a uniform solid sphere, what's ing with a period of 4 its angular momentum? 18-3 33. Example 11.2. The s 10-598 rpm With her arms outstre Section 11.4 Conservation of Angular Momentum tational inertia is 3.5 23. A potter's wheel with rotational inertia 6.20 kg•m? is spinning (Fig. 11.6b), her rot freely at 20.0 rpm. The potter drops a 2.50-kg lump of clay onto her final spin rate? L = 6 2 x 2-1 = 12-99~13 - 2x2 22 13= 60.48)" x 2.5 W W = 2 . X z W = 20x2T 60 ²2.1 ~ 1 12.574

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物理 高中

第21題 到底要怎麼寫ಥ_ಥ

Section 11.3 Angular Momentum J-s behind rmv a he ur 265 = ? a ter 30. Example 11.1: A 58.1 Iw COMP string and whirled at 18. Express the units of angular momentum (a) using only the funda- momentum of magr mental units kilogram, meter, and second; (b) in a form involving the circular path. Fir newtons; (c) in a form involving joules. marw horizontal and (b) the 19. Use data from Appendix E to make an order-of-magnitude esti- 31. Example 11.2. A stai mate for the angular momentum of our Solar System about the Max 27 the end of its lifetime galactic center. mu = 17.293 of radius 4.96 X 10' 20. A gymnast of rotational inertia 63 kg•m? is tumbling head over heels dwarf of radius 4.21 with angular momentum 460 kg•m?/s. What's her angular speed? 17.99 acted on the core, fine A 660-g hoop 95 cm in diameter is rotating at 170 rpm about its 32. Example 11.2: Astro 22. A 1.3-th-diameter golf ball has mass 45 g and is spinning at central axis. What's its angular momentum? L: 1W=0-66*(0-95) x 140x277.10 km and determin core that collapsed to 3000 rpm. Treating the golf ball as a uniform solid sphere, what's ing with a period of 4 its angular momentum? 18-3 33. Example 11.2. The s 10-598 rpm With her arms outstre Section 11.4 Conservation of Angular Momentum tational inertia is 3.5 23. A potter's wheel with rotational inertia 6.20 kg•m? is spinning (Fig. 11.6b), her rot freely at 20.0 rpm. The potter drops a 2.50-kg lump of clay onto her final spin rate? L = 6 2 x 2-1 = 12-99~13 - 2x2 22 13= 60.48)" x 2.5 W W = 2 . X z W = 20x2T 60 ²2.1 ~ 1 12.574

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