Newton's first law:
All bodies in any case,in the role of external force,always keep uniform linear motion relative static or state.
Example 1:an object static in horizontal desktop,if we don't have to move it force,it won't move.
1:this example that can prove objects from external (or in the case zero force to keep the stationary state unchanged.This is a kind of Newton's first law.
Example 2:a in the smooth level uniform motion object,if no external forces (friction force) to stop words,it will continue to keep moving forward.
2:this example that can prove objects from external (or in external condition) for zero to maintain motion state unchanged.This is the first law of Newton another kind of situation.
Newton's second law:
The acceleration of an object and the object of which is proportional to force by fits with the mass of the object,and the direction of the acceleration is inversely proportional to the direction closing an outside force.
Example 1:size two cars at the same speed,if at the same time the brake,then we will find the cart brake processes will slide further!
1:this example showed that the size of the force,the same circumstances,quality big object,the acceleration generated little (slippery far),this is qualitative proved Newton's second law.
Example 2:where we book that car drive tape movement experiments.
Instruction 2:in this experiment,we can know that the acceleration is g,through the measure time t and displacement s can quantitative proof F = mg.
Newton's third law of motion:
Between two objects reaction,the force and in the same line,equal,in opposite directions.
Example 1:two in ice skating,if one of them push another person's words,the two of them would be backward motion!
Explanation:this example,in A push in the process of B,B in turn also sending A,so they will all sport!This is Newton's third law must express!
Example 2:we punching walls.Will feel hand very ache,and the more you hard,hand more ache!
Explanation:this example showed two problems,1,people give wall a force wall also can give a person a force; 2,the force to the wall,the wall to the force.The man If there is CeLiJi words,we can also measure the size of the two forces as big!
为了便于你理解,中文如下：
牛顿第一定律：
一切物体在任何情况下,在不受外力的作用时,总保持相对静止或匀速直线运动状态.
例子1：一个物体静止在水平桌面上,如果我们不用外力去推动它,它是不会动的.
说明1：这个例子能证明物体在不受外力（或者外力为零的情况下）要保持静止状态不变.这就是牛顿第一定律的一种情况.
例子2：一个在光滑水平面匀速运动的物体,如果没有外力（摩擦等力）来阻止的话,它会继续保持向前运动的状态!
说明2：这个例子能证明物体在不受外力（或者外力为零的情况下）要保持运动状态不变.这就是牛顿第一定律的另一种情况.
牛顿第二定律：
物体的加速度跟物体所受的合外力成正比,跟物体的质量成反比,加速度的方向跟合外力的方向相同.
例子1：大小两辆车以相同的速度行驶,如果同时刹车的话,我们会发现大车刹车过程会滑行的更远!
说明1：这个例子说明,在力的大小一样的情况下,质量大的物体,所产生的加速度小（滑的远）,这就定性的证明了牛顿第二定律.
例子2：就是我们书上那个小车带动纸带运动的实验.
说明2：在这个实验中,我们可以知道加速度为g,通过测出时间t与位移s就可以定量的证明F=mg.
牛顿第三定律：
两个物体之间的作用力和反作用力,在同一直线上,大小相等,方向相反.
例子1：两个在冰面上滑冰的人,如果其中一人用力推另一个人的话,他们两个人都会向后运动!
说明：这个例子说明,在A推B的过程中,B反过来也在推A,所以他们才会都运动!这正是牛顿第三定律所要表达的!
例子2：我们用拳头打墙.会感觉手很疼,而且你越用力,手越疼!
说明：这个例子说明两个问题,1,人给墙一个力,墙也会给人一个力；2,人给墙的力越大,则墙给人的力也越大.如果有测力计的话,我们还可以测出这两个力的大小一样大的!
