Weight distribution
Encyclopedia
Weight distribution is the apportioning of weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...

within a vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....

, especially cars
CARS
Cars, or automobiles, motor cars, are wheeled motor vehicles used for transporting passengers.Cars or CARS may also refer to:-Entertainment:* Cars , a Disney/Pixar film series...

, airplanes, and trains.

In a vehicle which relies on gravity in some way, weight distribution directly affects a variety of vehicle characteristics, including handling
Car handling
Automobile handling and vehicle handling are descriptions of the way wheeled vehicles perform transverse to their direction of motion, particularly during cornering and swerving. It also includes their stability when moving at rest. Handling and braking are the major components of a vehicle's...

, acceleration
Acceleration
In physics, acceleration is the rate of change of velocity with time. In one dimension, acceleration is the rate at which something speeds up or slows down. However, since velocity is a vector, acceleration describes the rate of change of both the magnitude and the direction of velocity. ...

, traction
Traction (engineering)
Traction refers to the maximum frictional force that can be produced between surfaces without slipping.The units of traction are those of force, or if expressed as a coefficient of traction a ratio.-Traction:...

, and component life. Ideal weight distribution will vary from vehicle to vehicle and from application to application. For example, the weight distribution for a dedicated drag car
Drag racing
Drag racing is a competition in which specially prepared automobiles or motorcycles compete two at a time to be the first to cross a set finish line, from a standing start, in a straight line, over a measured distance, most commonly a ¼-mile straight track....

will be different from that of a car built for road racing
Road racing is a general term for most forms of motor racing held on paved, purpose-built race tracks , as opposed to oval tracks and off-road racing...

.

In the airline industry, load balancing is used to evenly distribute the weight of passengers, cargo, and fuel throughout an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

, so as to keep the aircraft's center of gravity
Center of gravity of an aircraft
The center-of-gravity is the point at which an aircraft would balance if it were possible to suspend it at that point. It is the mass center of the aircraft, or the theoretical point at which the entire weight of the aircraft is assumed to be concentrated. Its distance from the reference datum is...

close to its center of pressure to avoid losing pitch control. In military transport aircraft, it is common to have a loadmaster
A Loadmaster is an aircrew member on military transport aircraft. Loadmasters serve in the Air Force, Marines, Coast Guard and Navy of many nations...

as a part of the crew; their responsibilities include calculating accurate load information for center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...

calculations, and ensuring cargo is properly secured to prevent its shifting.

In large aircraft and ship
Ship
Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

s, multiple fuel tank
Fuel tank
A fuel tank is safe container for flammable fluids. Though any storage tank for fuel may be so called, the term is typically applied to part of an engine system in which the fuel is stored and propelled or released into an engine...

s and pumps are often used, so that as fuel is consumed, the remaining fuel can be positioned to keep the vehicle balanced, and to reduce stability problems associated with the free surface effect
Free Surface Effect
The free surface effect is one of several mechanisms which can cause a craft to become unstable and roll over . It refers to the tendency of liquids — and of aggregates of small solid objects, like seeds, gravel, or crushed ore which can act as liquids — to slosh about: to move in response to...

.

Weight Distribution is also now being applied in the field of human body measurement, using part volumes of the human body to determine where a patient’s weight is distributed and what health risks this may constitute. The Body Volume Index
Body volume index
The Body Volume Index is a new measurement for human obesity that has been proposed as an alternative to the Body Mass Index .BMI is based on a measurement of total mass, irrespective of the location of the mass, but BVI looks at the relationship between mass and volume distribution...

, links volume distribution of a patient’s 3D scan directly to their weight distribution using Body Composition
Body composition
In physical fitness, body composition is used to describe the percentages of fat, bone and muscle in human bodies. Because muscular tissue takes up less space in our body than fat tissue, our body composition, as well as our weight, determines leanness...

data.

• Center of mass
Center of mass
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body...

• Center of percussion
Center of percussion
The center of percussion is the point on an object where a perpendicular impact will produce translational and rotational forces which perfectly cancel each other out at some given pivot point, so that the pivot will not be moving momentarily after the impulse....

• Mass distribution
Mass distribution
Mass distribution is a term used in physics and mechanics and describes the spatial distribution of mass within a solid body. In principle, it is relevant also for gases or liquids, but on earth their mass distribution is almost homogeneous.-Astronomy:...

• Roll center
Roll center
The roll center of a vehicle is the notional point at which the cornering forces in the suspension are reacted to the vehicle body.-Theory:There are two definitions of roll center...

• Tilt test
Tilt test
The Tilt test is a type of safety test that certain government vehicle certification bodies require new vehicle designs to pass before being allowed on the road or rail track....

• Weight transfer
Weight transfer
Weight transfer and load transfer are two expressions used somewhat confusingly to describe two distinct effects: the change in load borne by different wheels of even perfectly rigid vehicles during acceleration, and the change in center of mass location relative to the wheels because of...

• Body Volume Index
Body volume index
The Body Volume Index is a new measurement for human obesity that has been proposed as an alternative to the Body Mass Index .BMI is based on a measurement of total mass, irrespective of the location of the mass, but BVI looks at the relationship between mass and volume distribution...