Questions | 5 |

Focus | Principles |

Topics | Mass, Newton's Second Law of Motion, Universal Gravitation, Weight |

Question Type | Questions |

Mass is a measure of the amount of matter in an object. In general, larger objects have larger mass than smaller objects but mass ultimately depends on how compact (**dense**) a substance is.

Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the **linear relationship** between mass and acceleration when it comes to force and leads to the formula **F = ma** or force equals mass multiplied by rate of acceleration.

Newton's Law of Univeral Gravitation defines the general formula for the attraction of gravity between two objects: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) . In the specific case of an object falling toward Earth, the **acceleration due to gravity** (g) is approximately 9.8 m/s^{2}.

Mass is an intrinsic property of matter and does not vary. Weight is the force exerted on the mass of an object due to gravity and a specific case of Newton's Second Law of Motion. Replace force with weight and acceleration with acceleration due to gravity on Earth (g) and the result is the formula for weight: **W = mg** or, substituting for g, weight equals mass multiplied by 9.8 m/s^{2}.