力学知识的广泛应用
1.重力的应用
我们生活在地球上,重力无处不在。如工人师傅在砌墙时,常常利用重锤线来检验墙身是否竖直,这是充分利用重力的方向是竖直向下这一原理;羽毛球的下端做得重一些,这是利用降低重心使球在下落过程中保护羽毛;汽车驾驶员在下坡时关闭发动机还能继续滑行,这是利用重力的作用而节省能源;在农业生产中的抛秧技术也是利用重力的方向竖直向下。假如没有重力,世界不可想象,水不能倒进嘴里,人们起跳后无法落回地面,飞舞的尘土会永远漂浮在空中,整个自然界将是一片混浊。在讲授重力时,要让学生展开热烈的讨论,充分挖掘学生的想象力,知道重力与我们的生产生活实际密切相关。
2.摩擦力的应用
摩擦力是一个重要的力,它在社会生产生活实际中应用非常广泛。如人们行走时,在光滑的地面上行走十分困难,这是因为接触面摩擦太小的缘故;汽车上坡打滑时,在路面上撒些粗石子或垫上稻草,汽车就能顺利前进,这是靠增大粗糙程度而增大摩擦力;鞋底做成各种花纹也是增大接触面的粗糙程度而增大摩擦;滑冰运动员穿的滑冰鞋安装滚珠是变滑动摩擦为滚动摩擦,从而减少摩擦而增大滑行速度;各类机器中加润滑油是为了减小齿轮间的摩擦,保证机器的良好运行。可见,人类的生产生活实际都与摩擦力有关,有益的摩擦要充分利用,有害的摩擦要尽量减少。
3.弹力的应用
利用弹力可进行一系列社会生产生活活动,力有大小、方向、作用点。如高大的建筑需要打牢基础,桥梁设计需要精确计算各部分的受力大小;拔河需要用粗大一些绳子,防止拉力过大导致断裂;高压线的中心要加一根较粗的钢丝,才能支撑较大的架设跨度;运动员在瞬间产生的爆发力等等。
可见,物理力学知识生产和生活实际中是很有用的,从宇宙天体到微观的分子、原子处处存在着各种各样的力,教师只要将课本知识与生产生活实际有机地结合起来,就能极大地激发学生的学习兴趣,从而培养他们树立崇尚科学、研究科学、应用科学精神。
二、热学知识的应用
天气的阴晴、冷暖与人类的各类活动息息相关,包含了很多的物理热学知识。如人们常喝开水、吃熟食,需要对水和食物进行加热,而加热过程中就需知道燃料燃烧或电力加热的基本知识;炎热的夏天在地上撒些水,靠水分的蒸发达到降温的目的;严寒的冬天如何保暖,汽车发动机常用水来散热,保护秧苗不被冻坏而往往采用在夜间向稻田里灌水,都充分利用了水的比热大这一特性;水稻生长在夏季,是由于水稻是喜高温的植物
The wide application of mechanical knowledge
1. Gravitational application
We live on the earth, gravitational nowhere is absent. If worker master worker is when wall of build by laying bricks or stones, often use heavy weight line to examine wall body whether upend, this is to make full use of gravitational direction is upend is down this one principle; The lower end of badminton is done a few againer, this is to use reduce centre of gravity to make the ball protects feather in whereabouts process; Car driver is in declivous when shut engine to still can continue to glide, this is use gravitational function and save the sources of energy; The technology casting fry in agricultural production also is to use gravitational directional upend to be down. If do not have gravity, the world is inconceivable, water cannot fall into the mouth, a ground cannot fall after people takes off, the dust that flutter can float in sky forever, whole nature will be muddy. When tuitional gravity, want to let a student spread out a harangue, dig the student's imagination adequately, the manufacturing life that knows gravity and us is real closely related.
2. The application of attrition force
Attrition force is a fundamental strength, it produces the life is real medium applying in the society very extensive. When walking like people, it is very difficult to walk on glossy floor, because interface chafes,this is too small cause; When the car skids uphill, the straw on some of thick cobble or mat is scattered on road surface, the car can advance smoothly, this is to rely on to increase crude rate and increase attrition power; Sole make it all sorts of decorative pattern also are the crude rate that increases interface and increase attrition; The ball of ice skates installation that the skater wears is to change sliding friction is rolling friction, reduce attrition thereby and increase glide speed; Lubricating oil is being added in of all kinds machine is to reduce the attrition between gear, assure the good fortune of the machine to go. Visible, human production lives to be concerned actually with attrition force, beneficial attrition should make full use of, harmful attrition should decrease as far as possible.
3. The application of bounce
Use bounce to be able to undertake a series of societies manufacture life activity, force has place of size, direction, action. If tall building needs to lay firm foundation, bridge design need is calculated accurately the size getting power of departmental cent; Tug-of-war needs to use a few bulkier cord, prevent pulling force to be brought about greatly too rupture; The center of the high tension line should add a thicker steel wire, ability props up bigger erect span; The outbreak that the athlete produces in the instant force is waited a moment.
Visible, mechanical knowledge produces physics and the life is real in it is very useful, existing everywhere to microcosmic element, atom from cosmic celestial bodies various force, the teacher wants to live textbook knowledge and production only union of actual and organic ground rises, learn interest with respect to what can arouse a student greatly, foster them to establish thereby advocate spirit of science, research science, technology.
2, the application of heat knowledge
The be closely bound up of of all kinds activity of the Yin Qing of weather, changes in temperature and mankind, included a lot of physical heat knowledge. Like people tipple boiled water, eat cooked food, need undertakes heating to water and food, and heat the basic knowledge that needs to know fuel burns or electric power heats in the process; Burning hot summer sprinkles some of water on the ground, rely on the evaporate of moisture to develop to the purpose that drop in temperature; Freezing winter how heat preservation, car engine is commonly used water will come loose hot, protective seedling is not frozen bad and often use in nightly to water of the fill in the rice field, made full use of the specific heat of water is big this one character; Paddy grows in the summer, because paddy is the plant that is fond of high temperature,be