请对物理零基础的8年级的孩子讲解图片涉及到的物理知识，要求把字母的定义，概念和公式如何推导都讲解清楚---**Extraction Content:** **Title:** 滑轮组的特点 (Characteristics of pulley systems) **Diagrams and Descriptions:** The image displays four different pulley systems side-by-side, shown against a green background. Below each diagram are mathematical formulas. **Diagram 1:** * **Type:** Pulley system diagram. * **Elements:** One fixed pulley at the top, one movable pulley below it. A rope passes over the fixed pulley, wraps around the movable pulley, and is pulled upwards by a force labeled 'F'. The load labeled 'G' is attached to the movable pulley. An arrow indicates the upward direction of force F. Another arrow indicates the upward direction of the load G. The rope segments supporting the movable pulley and the load are shown. * **Associated Formulas:** * F = (1/2)G * s = 2h **Diagram 2:** * **Type:** Pulley system diagram. * **Elements:** One fixed pulley at the top, one movable pulley below it. A rope is attached to the fixed support, passes around the movable pulley, then over the fixed pulley, and is pulled upwards by a force labeled 'F'. The load labeled 'G' is attached to the movable pulley. An arrow indicates the upward direction of force F. Another arrow indicates the upward direction of the load G. The rope segments supporting the movable pulley and the load are shown. * **Associated Formulas:** * F = (1/3)G * s = 3h **Diagram 3:** * **Type:** Pulley system diagram. * **Elements:** Two fixed pulleys at the top (side-by-side on the same support bar), two movable pulleys below them. A rope is attached to the fixed support, passes around the first movable pulley, then over the first fixed pulley, then around the second movable pulley, then over the second fixed pulley, and is pulled upwards by a force labeled 'F'. The load labeled 'G' is attached to the block containing the two movable pulleys. An arrow indicates the upward direction of force F. Another arrow indicates the upward direction of the load G. The rope segments supporting the movable pulleys and the load are shown. * **Associated Formulas:** * F = (1/4)G * s = 4h **Diagram 4:** * **Type:** Pulley system diagram. * **Elements:** Two fixed pulleys at the top, two movable pulleys below them. A rope is attached to the fixed support, passes around the first movable pulley, then over the first fixed pulley, then around the second movable pulley, then over the second fixed pulley, and finally is pulled upwards by a force labeled 'F'. The load labeled 'G' is attached to the block containing the two movable pulleys. An arrow indicates the upward direction of force F. Another arrow indicates the upward direction of the load G. The rope segments supporting the movable pulleys and the load are shown. This diagram appears identical to Diagram 3 in terms of pulley arrangement and connections, but the formula suggests a different interpretation (perhaps the attachment point or starting point of the rope is different, or there's a mistake in the diagram/formula pairing). However, based solely on the visual representation and formulas provided: * **Associated Formulas:** * F = (1/5)G * s = 5h **Header:** 天津外国语大学附属滨海外国语学校 **Content:** **Diagram 1:** * **Type:** Pulley system diagram. * **Elements:** One fixed pulley at the top, one movable pulley attached to a load (square block) below. Rope starts from a fixed support, goes around the movable pulley, then around the fixed pulley, and the force F is applied upwards on the free end. * **Labels/Annotations:** '定' (Fixed) next to the top pulley, '动' (Movable) next to the bottom pulley. Downward arrow next to the load. Upward arrow for force F. n=2 below the load. * **Associated Text:** * F = (1/2)(G + G_动) * S = 2h * V_绳 = 2V_物 **Diagram 2:** * **Type:** Pulley system diagram. * **Elements:** One fixed pulley at the top, one movable pulley attached to a load (square block) below. Rope starts from the movable pulley assembly, goes up around the fixed pulley, down around the movable pulley, and the force F is applied upwards on the free end. * **Labels/Annotations:** '定' (Fixed) next to the top pulley, '动' (Movable) next to the bottom pulley. Downward arrow next to the load. Upward arrow for force F. n=3 below the movable pulley. * **Associated Text:** * F = (1/3)(G + G_动) * S = 3h * V_绳 = 3V_物 **Diagram 3:** * **Type:** Pulley system diagram. * **Elements:** One fixed pulley at the top, one movable pulley attached to a load (square block) below. Rope starts from the movable pulley assembly, goes up around the fixed pulley, down around the movable pulley, up around the fixed pulley again, and the force F is applied downwards on the free end. * **Labels/Annotations:** '定' (Fixed) next to the top pulley, '动' (Movable) next to the bottom pulley. Downward arrow next to the load. Downward arrow for force F. n=3 below the movable pulley. * **Associated Text:** * F = (1/3)(G + G_动) * S = 3h * V_绳 = 3V_物 **Diagram 4:** * **Type:** Pulley system diagram. * **Elements:** Two fixed pulleys at the top, one movable pulley attached to a load (square block) below. Rope starts from a fixed support, goes around the movable pulley, up around the left fixed pulley, down around the right fixed pulley, and the force F is applied downwards on the free end. * **Labels/Annotations:** '定' (Fixed) next to both top pulleys, '动' (Movable) next to the bottom pulley. Downward arrow next to the load. Downward arrow for force F. n=4 below the movable pulley. * **Associated Text:** * F = (1/4)(G + G_动) * S = 4h * V_绳 = 4V_物 **Diagram 5:** * **Type:** Pulley system diagram. * **Elements:** Two fixed pulleys at the top, two movable pulleys attached to a load (square block) below. Diagram shows a rope path with 4 segments supporting the load. (Description based on n=4). * **Labels/Annotations:** '定' (Fixed) next to the two top pulleys. Downward arrow next to the load. Downward arrow for force F. n=4 below the load. * **Associated Text:** * F = (1/4)(G + G_动) * S = 4h * V_绳 = 4V_物 **Diagram 6:** * **Type:** Pulley system diagram. * **Elements:** Two fixed pulleys at the top, three movable pulleys attached to a load (square block) below. Diagram shows a rope path with 5 segments supporting the load. (Description based on n=5). * **Labels/Annotations:** '定' (Fixed) next to the two top pulleys, '动' (Movable) next to the three bottom pulleys. Downward arrow next to the load. Downward arrow for force F. n=5 below the load. * **Associated Text:** * F = (1/5)(G + G_动) * S = 5h * V_绳 = 5V_物 **General Formulas/Notes:** * n: 动滑轮上绳子的段数 (n: Number of rope segments on the movable pulley) * F = (1/n)(G + G_动) (Ignoring rope weight and friction) * S = nh * 不计绳重和摩擦 (Ignoring rope weight and friction) * 奇动偶定 (Odd [n] starts from movable pulley assembly, Even [n] starts from fixed support) * 奇动: n=1/3/5 * 偶定: n=2/4