想請問關於繩張力的問題，書上跟網路上看到繩張力公式為m(g+a) 請問加速度有分正負嗎？以圖片中的37題來講，如果繩子及物體是以2m/s^2往下而非網上的話，繩張力是否會變成m(g-2)呢？ 感謝各位

若十m/s? (A)2 (B)2.5 (C)2.75 Am SS D₁ (D)) 2.0.11 HOMM2014 IOE HAVE 00 (4) 11 ( v=1m/s FRH 37 粗細均勻之繩,長1公尺而質量2公斤,現在其下端掛質量4公斤物體,並於繩上端施 頓向上之力鉛直上拉,g=10m/s²,試問距繩掛物端25公分處之繩張力大小為若干牛頓 BA) 49 (A)49 (B)54 (C)59 (D)64 (E)69) JOHIN 60 N 40 45NV 9=2 T=Mg+ma 22 31 HORAS t

想問這兩題 麻煩了

想問這題😥

想問（2）（3）🙏

請問一下第（6）小題🙏

想請問一下這兩題🙏

求解

類題 3.1 右圖為一光纖之側面剖面圖,其中n 及 n, 分別代表不同物質之折射 率,n 之部分稱為核心。若要使光在核心中靠全反射傳遞,則sin0 的 最大值為 loa+3=90° sina = Cosp 1 x sing = h, x sina :hi xausB 閤:√n^-n 2 0 中心軸 n=1 nistro₂ =n₂sin D₂ R. n₂ n₁ M₂

B是答案，但波爾氫原子理論不是有能量嗎？

Which issue in the spectrum of hydrogen atoms can not be solved by the Bohr model? (A) The existence of separated series of lines; (B) The relative intensity of each line; (C) The wavelength of each line; (D) All; (E) None.

C

Which statement is not correct according to the "theory of special relativity"? (A) Whether two events at different locations are simultaneous depends on the frame; (B) The relative velocity of two objects never precede the speed of light; (C) The "effect" may appear to occur earlier than its "cause" as observed in some frames; (D) All; (E) None.

到底在幹嘛😵‍💫

A better resolution for the two headlights of a car in a picture can be achieved by reducing (A) the separation of the headlights; (B) the wavelength of light; (C) the aperture diameter of the camera lens; (D) All; (E) None.