年級

問題的種類

物理 高中

(第一張照片)守恆的概念是沒問題的,但換符號好像有點問題,mg是怎麼換成mV/r的???還有a是怎麼換成V^2/r的???感覺是我前面換算學得不太好的關係🥺 (第二張照片)想知道c選項的算式是怎麼來的?

範例3 圓周運動的力學能守恆 雲飛車是一種常見於主題樂園中的遊樂設施, ao 其軌道通常有如圖所示的迴圈。若考慮正圓的迴 圈軌道,且軌道可視為在一鉛直面上,雲霄飛車 的車廂在沒有動力驅動之下,沿著軌道內側繞行, 且軌道只能提供向心力,摩擦阻力可忽略,重力 加速度為g,則當車廂可沿整個圓圈軌道繞行時,車廂在軌道最低點的加速度量值至少 為何? (A) 2g (B) 3g (C) 4g (D) 5g (E) 6g 向心力: V₁ F=mg= m JJR VH R + a₁ = JEJR (JSJR) R V₁ R 1=5g A.0) 願選一條長為R的繩子綁住一個石塊,讓石塊一開始在鉛直面上作圓周運 動,石塊的位置可由石塊—圓心連線和水平線夾角表示,如右圖所 Mo 示。若石塊在最低處的速率改為 7gR g為重力加速度,則石塊轉 2 到何處時會脫離如圖所示之圓形虛線軌跡?(已知sin37°=0.6) (A)=30° (B)=37° (C)=45°(D)=53°E=60° R my mg cose 79R 2 ① 力学能守恆 /m() :/mv+mgal1+sine) myR 2 → v² 1 gk (3-4 sino) ② 圓周運動(向心力:張力、動) T+ mg sino - V = 1mg (3-4 sino) →繩鬆⇒7:0 →脫離:與最低點高度差h " R+R Sind ⇒ 0+mg sine = 1 mg (3-45/40> : R(1+ Sine) => sino 0-300 【107. 指考】

待回答 回答數: 0
數學 國中

求解🙏

( 34.~35.) Hi, I am Jamie. My special place is in a big apple tree by my grandparents' garden. My grandpa built it for my sister and me. To get there, I have to climb up a ladder. Grandpa built it with wood and it also has a roof, so we don't get wet when it rains. I like to sit inside when it rains. The sound makes me comfortable. Sometimes I have food with my sister and cousins there. One day, I wanted to spend the night there, but it was really dark. I was afraid, so I went back to the house. vobiulp? Hi, my name is Karen. My special place is in a park near my home. I go there with my friends. It is not in the center of the park, so few people go there. There is a bench under a tree, and we often sit and talk there. It makes us very happy. There is a beautiful fountain and we often play water in it. It is a great place when the weather is hot. The tall trees there can help us keep out of the sun. In the spring, there are many beautiful flowers. It is more like the country than a park in the city. ladder 梯子 wood木材 roof屋頂 fountain 噴泉 34. Which is the right picture of the special place? (A) Jamie's m.q08 (B) Jamie's uto2 mw onex99W DD 21 Did b Yoineetblirb JUC r t'nob uoY chowezuor apnhd ne .2M dor by glori abbl (C) Karen's (D) Karen's 91blirb ynoma ob of mert b9b not agit aw? smol law by slows bas ov w.moo.zhit.www Jiziv To 1200-0588-40 ( ) 35. Which is NOT true? almid (A) Karen's special place is in the city. wla naniol" bina bom e vodol25 (B) Karen likes to play water with her friends. W mid 10 taong i sno zirli (C) Jamie stayed in his favorite place for nights. (D) There is a garden next to Jamie's special place. smol Jow? (A) M() .smita coin2.0

待回答 回答數: 0