This formula combines two basic laws : newton ' s law of gravity ( which relates the force of gravity between bodies to the bodies ' masses and separation ) and newton ' s second law ( which relates force to acceleration ) 这个公式结合了两项基本定律:万有引力定律(即两物体间的重力是和物体的质量与距离有关)以及牛顿第二运动定律(力和加速度的关系) 。