中考物理基础学问（六）: 功、机械能和浅易机械潜江铁皮保温施工队

Basic Physics Knowledge for the Senior High School Entrance Examination (VI): Work, Mechanical Energy and Simple Machines

李宏 湖北省十堰市郧阳中学

Li Hong Yunyang High School, Shiyan City, Hubei Province

十章 功和机械能-[中考物理基础学问]

Chapter 11: Work and Mechanical Energy - [Basic Physics Knowledge for High School Entrance Examination]

65．功的两个身分：

The two essential factors of work:

（1）作用在物体上的力；

The force acting on an object;

（2）物体在这个力的朝上挪动的距离。

The distance moved by the object in the direction of the force.

66．功的谋划：W=FS

Calculation of work: W=F⋅s

67．功的旨趣：使用任何机械王人不省功。

Principle of work: No machine can save work.

68．功率的谋划：（ W=Pt ）。功率的公式：P=Fv

Calculation of power: (W=P⋅t) 。The derived formula for power: P=F⋅v

69．物体由于指令而具有的能量叫动能，动能的大小与物体的质地和物体指令的速率联系，且指令速率对动能的影响较大。

The energy possessed by an object due to its motion is called kinetic energy. The magnitude of kinetic energy depends on the mass of the object and its velocity, with velocity having a greater impact on kinetic energy.

70．物体由于度所具有的能量叫重力势能潜江铁皮保温施工队。

The energy possessed by an object due to its height is called gravitational potential energy.

重力势能的大小与物体的质地和物体被举起的度联系。

The magnitude of gravitational potential energy depends on the mass of the object and the height to which it is raised.

71．物体由于发生弹形变而具有的能量叫弹势能。

The energy possessed by an object due to elastic deformation is called elastic potential energy.

弹势能的大小与物体发生弹形变的流程和物体的材料、质联系。

The magnitude of elastic potential energy depends on the degree of elastic deformation and the material and properties of the object.

十二章 浅易机械-[中考物理基础学问]

Chapter 12: Simple Machines - [Basic Physics Knowledge for High School Entrance Examination]

72．根硬棒，在力的作用下能绕着固定点动弹，这根硬棒等于杠杆。

A lever is a rigid bar that rotates around a fixed point when force is applied.

支点：杠杆绕着动弹的点；

Fulcrum: the point around which the lever rotates;

能源：使杠杆动弹的力；

Effort: the force that causes the lever to rotate;

阻力：扯后腿杠杆动弹的力；

Resistance: the force that opposes the rotation of the lever;

能源臂：从支点到能源作用线的距离；

Effort arm: the perpendicular distance from the fulcrum to the line of action of the effort;

阻力臂：从支点到阻力作用线的距离。

Resistance arm: the perpendicular distance from the fulcrum to the line of action of the resistance.

73．杠杆的均衡要求：能源×能源臂＝阻力×阻力臂 即 F1L1＝F2L2

Lever equilibrium condition:

Effort × Effort arm = Resistance × Resistance arm, i.e., F1L1＝F2L2

74．杠杆的运用：

Applications of levers:

（1）省力杠杆：L1＞L2 F1＜F2 省力费距离；（钢丝钳、撬棒）

Effort-saving lever: L1>L2, F1<F2, saves effort but requires more distance (e.g., wire pliers, pry bar).

（2）勉力杠杆：L1＜L2 F1＞F2 勉力省距离；（镊子、筷子）

Effort-intensive lever: L1<L2, F1>F2, requires more effort but saves distance (e.g., tweezers, chopsticks).

（3）等臂杠杆：L1= L2 F1= F2 不省力、不省距离，能转变力的向。（天平）

Equal-arm lever: L1=L2, F1=F2, neither saves effort nor distance but can change the direction of force (e.g., balance scale).

75．定滑轮的试验是等臂杠杆，设备保温施工不错转变力的向；

A fixed pulley is essentially an equal-arm lever, which can change the direction of force.

动滑轮的试验是能源臂等于阻力臂2倍的杠杆，不错省半的力。

A movable pulley is essentially a lever where the effort arm is twice the resistance arm, saving half the effort.

76．使用滑轮组时，滑轮组用几段绳索吊注意物，绳索摆脱端的拉力等于物重的几分之。

When using a pulley system, the tension in the free end of the rope is a fraction of the weight of the load, depending on the number of rope segments supporting the load.

且物体升“h”，则绳索摆脱端挪动“s=nh”，其中“n”为绳索的段数。

If the load is raised by a height "h", the free end of the rope moves a distance "s = n h", where "n" is the number of rope segments.

77．机械率：滑轮组的机械率、斜面的机械率

Mechanical efficiency: Mechanical efficiency of pulley systems, mechanical efficiency of inclined planes.

Explorer of Innovative Thinking

Author: Li Hong

Yunyang High School, Shiyan City, Hubei Province

February 6潜江铁皮保温施工队, 2026