Questions | 5 |

Topics | Building Loads, Newton's Second Law of Motion, Weight, Work |

**Dead load** is the weight of the building and materials, **live load** is additional weight due to occupancy or use, **snow load** is the weight of accumulated snow on a structure and **wind load** is the force of wind pressures against structure surfaces.

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.

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}.

Work is accomplished when force is applied to an object: **W = Fd** where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done.