第1个回答 2022-10-30
牛顿吧.. 牛顿运动定律是伊萨克·牛顿提出了物理学的三个运动定律的总称，被誉为是经典物理学的基础。 牛顿第一运动定律：当物体不受外力作用，或所受合力为零时，原先静止者恒静止，原先运动者恒沿着直线作等速度运动。这定律又称为「惯性定律」。 牛顿第二运动定律：物体受力后其动量变化率，和其所受的净力（即合力）成正比，及处于同一方向。 牛顿第三运动定律：当两物体交互作用时，彼此互以力作用于对方，两者大小相等，方向相反，但作用在不同的物作用体上。这定律又称为「作用与反作用定律」。
Newton's laws of motion(1670s) Newton's first law: If an object is at rest
or if its speed and direction are constant
then the resultant force on it is zero(Force on the object below are equal-no resultant force
so no acceleration. Newton's second law: If the momentum of an object changes
eg. if it accelerates
then there must be resultant force acting on it. Normally
the mass of the object is constant
and the force is thus proportional to the acceleration of the object. The direction of the acceleration is the same as the direction of the force. (Formula: F=ma F=Force
M=mass
a=acceleration) Newtons third law: Forces always occur in equal and opposite pairs called the *action and *reaction. Thus if object A exerts a force on object B
object B exerts an equal but opposite force on A. These forces *do not cancel each other out
as they act on different objects. Hope this would be useful for you :-) 2008-12-31 19:39:15 补充： Example for Newton's third law: Bat exerts force on ball
accelerating it in opposite direction. Ball exerts equal and opposite force on bad(felt as sudden slowing down of bat)