Newton"s second law of motion states that the force needed to accelerate a particle is equal to the product of the mass of the particle and the acceleration produced.牛頓第二定律指:使質點加速的力等於質點的質量乘以力所產生的加速度。也就是F=maThe unit of force is the newton(N). It is defined as the force that will cause a mass of 1 kg to accelerate at a rate of 1 m/s^2力的單位是牛頓N,1N等同於使1kg的物質產生1m/s^2的加速度時所用的力。you usually resolve in the direction of the acceleration and perpendicular to the direction of the acceleration我們通常(將力)分解為一個加速度方向的力和一個垂直於加速度方向的力。the normal reaction is the force which acts perpendicular to a surface when an object is in contact with the surface. In the example on the previous page, the normal reaction is equal in magnitude to the weight of the book反作用力垂直於物體的接觸面,在前頁的例子中,反作用力的大小等於書地重力。
Newton"s second law of motion states that the force needed to accelerate a particle is equal to the product of the mass of the particle and the acceleration produced.牛頓第二定律指:使質點加速的力等於質點的質量乘以力所產生的加速度。也就是F=maThe unit of force is the newton(N). It is defined as the force that will cause a mass of 1 kg to accelerate at a rate of 1 m/s^2力的單位是牛頓N,1N等同於使1kg的物質產生1m/s^2的加速度時所用的力。you usually resolve in the direction of the acceleration and perpendicular to the direction of the acceleration我們通常(將力)分解為一個加速度方向的力和一個垂直於加速度方向的力。the normal reaction is the force which acts perpendicular to a surface when an object is in contact with the surface. In the example on the previous page, the normal reaction is equal in magnitude to the weight of the book反作用力垂直於物體的接觸面,在前頁的例子中,反作用力的大小等於書地重力。