請問例題7怎麼算

《Example 7》- 邊長a之均勻立方體木塊,比重為p,浮在比重為d之液體中(d>p),問: (a)欲使木塊全部沒入液中,至少需作功若干? (b)若木塊恰完全沒入液面時,再使其深入,至少需作功若干?

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

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

如何算碰撞時間距縮短量(D)選項

(Example 4) 1 -1 8 H2 于 I " 在一直線上的甲、乙兩球發生正面碰撞,而兩球碰撞前到碰撞後的速度時 間變化的關係如圖所示,則 (0)甲:(上 。 b 2.2 (A)此碰撞為非彈性碰撞 4 (B)整個碰撞過程費時0.5 秒 4 Ti - (C)在0.75 秒時兩物最接近,此時兩均以3m/s的速度運動 (D)由碰撞開始至最接近,兩者間距缩短75cm ) (E)甲、乙兩物的質量比為1:2 5、 5 4 二 +/db -loo 4 - 一1 5 ps 14中 v(m/s) ly 2 士 pp.11 ou 5 ()- t 0 ) O 2. 2.27 十 4 3 N. 4 4 4 m/4 印 3. L ), stoly 3 6.5. Och Is. o 2 0 0 - 1 甲 0 t(s) 0.5 0.75 1 大王或小

我是不是少考慮了什麼🤔 答案C

《Example 11》 兩個螺線的外形(斷面和管長等)一樣,且各用不同粗細(斷面半徑各為11, 72)及不同數(Ni 及N),但同一質料(比電阻)的銅線繞成。為了在管 內產生同樣的磁場,加於各線圈的電功率 P及P之比P2/Pi 為 (A) r1N2/r2Ni (B) r2N2/rıNı (C) rı?N,/r2²N2 (D) rı2N2/r22N; (E) 1 °(E)

求解

《Example 1 2010 年諾員兩物理獎。 頒給研 膠合住攻片兩同,撕開膠估7 點炊。石點才為單層碳原子 彌吾72K。石曙燃被認為是世界上 最後得到單層碳原子的石 長為014款米狀似蜂巢的正六邊形構造, 最薄、最堅硬、導電能力最好的物質。 基本上呈透明狀,但極為密實, 氣體 比鑽石還堅硬,但卻可 以像拉攀膠一樣對它 和液體都無法滲透。石墨燃雖然 進行拉伸。請根據以上敘述回答下列問題: 原子,同時被數個正六 (A) 13 (B) 12《 (b) 已知標準籃球場的