Equations of motion system). Particle does not exert a torque on itself. Some examples of Newton's law include describing the motion of a simple pendulum, and a damped, sinusoidally driven harmonic oscillator, For describing the motion of masses due to gravity, Newton's law of gravity can be combined with Newton's second law. For two examples, a ball of mass thrown in the air, in air currents (such as wind) described by a vector field of resistive forces , where is the gravitational constant, the mass of the Earth, and is the acceleration of the projectile due to the air currents at position and
Three Laws of Robotics the editor of "Astounding Science-Fiction". Campbell rejected it, claiming that it bore too strong a resemblance to Lester del Rey's "Helen O'Loy", published in December 1938; the story of a robot that is so much like a person that she falls in love with her creator and becomes his ideal wife. Frederik Pohl published "Robbie" in "Astonishing Stories" magazine the following year. Asimov attributes the Three Laws to John W. Campbell, from a conversation that took place on 23 December 1940. Campbell claimed that Asimov had the Three Laws already in his mind and that they simply needed to be