請問這題是怎麼算出來的😥

類題:三個完全相同之金屬球A、B 和 C,其中A、B兩球各帶電-Q及+2,位 置固定,但 C球不帶電。若A、B之距離d遠大於球的半徑,其間靜電力為F。今將C與A接觸, 移開後再與B接觸,然後移到遠處,則最後A、B間靜電作用力為何? 5 A AM/FB/F OFF OF (A) (B) (C)- (D) 16 A 13 3 16 (E) 16 答:B

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.

A答案，求救

A laser beam of intensity S and cross-sectional area A is completely absorbed by a particle of mass m for a period At. What is the change in speed of the particle? (A) SAAt/mc; (B) SAAt/m; (C) SA/mc; (D) SAAt/c; (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.

救我感恩您

Which is not an appropriate pair of analogy between mechanical and electrical quantities of the oscillating systems? (A) x➜ Q; (B) v ←➜1; (C) m← C; (D) F→ V; (E) None.

😀

(B) the current; (C) the sign and concentration of charge carriers; (D) All; (E) None. A particle of mass m and charge q is in a circular orbit (of radius R) normal to an external field B. What is proportional to the magnetic field created at the center of its orbit by the charge? (A) m; (B) q; (C) R; (D) B; (E) None.

救命啊

A point charge Q is placed at one corner of a Gaussian surface in the form of a cube of side L. What is the total "electric flux" through this Gaussian surface in terms of Q/ & o? (A) 0; (B) 1/8; (C) 3/4; (D) 5/6; (E) None. Which is not correct for the dielectric constant (x) of a substance? (A) It is a measure

哈囉，拜託誰能救一下

One mole of an ideal monatomic gas is taken around the reversible cycle shown in Figure.1 (on the right). What is the efficiency of this "heat engine"? (A) 4/21; (B) 5/14; (C) 6/11; (D) 7/34; (E) None. 3Po Por 4 a Q4 d Vo est C Q2 2%

要死了🥲

Which statement is not correct for the "shear modulus"? (A) It has the same dimension as the "pressure"; (Bt involves the application of two parallel forces of opposite directions along the same line; (C) It can not be defined for an ideal fluid; (D) All; (E) None.