First law: a rigid body continues in a state of rest or a uniform motion in a straight line unless it is acted upon by external forces<\/p>\n
Second law: the rate of change in the linear momentum of a rigid body is proportional to and in the same direction as the force applied. If the mass remains constant, then F = ma<\/span> [i.e., the force (F) is equal to the product of mass (m<\/span>) and acceleration (a<\/span>)].<\/p>\n Third law: if one rigid body exerts a force on another, then there is an equal and opposite force (i.e., ‘for every action there is an equal and opposite’, a popular way of describing this law, but one that is open to misinterpretation). <\/p>\n With tongue in cheek, the science cartoonist Sydney Harris<\/a> added another law to Newton’s three: <\/p>\n Fourth law: physicists get together regularly in unknown European towns to make a group picture and disperse afterward.<\/p>\n See Biomechanics<\/a>, Constraint<\/a>, Dynamics<\/a>, Force<\/a>, Inertia<\/a>, Kinetics<\/a>, Laws of nature<\/a>, Linear dynamical systems<\/a>, dynamics<\/a>, Model<\/a>, Newton’s law of universal gravitation<\/a>, Newtonian (or classical) mechanics<\/a>, Tautology<\/a><\/p>\n <\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":" First law: a rigid body continues in a state of rest or a uniform motion in a straight line unless it is acted upon by external forces Second law: the rate of change in the linear momentum of a rigid body is proportional to and in the same direction as the force applied. If the mass remains … <\/p>\n