# Mass vs. Weight

By Jaxson

## Main Difference

The main difference between Mass and Weight is that the Mass is a measure of the resistance of a physical body to acceleration; also determines the strength of its gravitational attraction and Weight is a force on the object due to gravity.

• Mass

Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied. The object’s mass also determines the strength of its gravitational attraction to other bodies.

The basic SI unit of mass is the kilogram (kg). In physics, mass is not the same as weight, even though mass is often determined by measuring the object’s weight using a spring scale, rather than balance scale comparing it directly with known masses. An object on the Moon would weigh less than it does on Earth because of the lower gravity, but it would still have the same mass. This is because weight is a force, while mass is the property that (along with gravity) determines the strength of this force.

• Weight

In science and engineering, the weight of an object is related to the amount of force acting on the object, either due to gravity or to a reaction force that holds it in place.

Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force. Others define it as the magnitude of the reaction force exerted on a body by mechanisms that keep it in place: the weight is the quantity that is measured by, for example, a spring scale. Thus, in a state of free fall, the weight would be zero. In this sense of weight, terrestrial objects can be weightless: ignoring air resistance, the famous apple falling from the tree, on its way to meet the ground near Isaac Newton, would be weightless.

The unit of measurement for weight is that of force, which in the International System of Units (SI) is the newton. For example, an object with a mass of one kilogram has a weight of about 9.8 newtons on the surface of the Earth, and about one-sixth as much on the Moon. Although weight and mass are scientifically distinct quantities, the terms are often confused with each other in everyday use (i.e. comparing and converting force weight in pounds to mass in kilograms and vice versa).

Further complications in elucidating the various concepts of weight have to do with the theory of relativity according to which gravity is modelled as a consequence of the curvature of spacetime. In the teaching community, a considerable debate has existed for over half a century on how to define weight for their students. The current situation is that a multiple set of concepts co-exist and find use in their various contexts.

Wikipedia
• Mass (noun)

Matter, material.

• Mass (noun)

A cohering together so as to make one body, or an aggregation of particles or things which collectively make one body or quantity, usually of considerable size

• Mass (noun)

Precious metal, especially gold or silver.

• Mass (noun)

The quantity of matter which a body contains, irrespective of its bulk or volume. It is one of four fundamental properties of matter. It is measured in kilograms in the SI system of measurement.

• Mass (noun)

A medicinal substance made into a cohesive, homogeneous lump, of consistency suitable for making pills; as, blue mass.

• Mass (noun)

A palpable or visible abnormal globular structure; a tumor.

• Mass (noun)

Excess body weight, especially in the form of muscle hypertrophy.

• Mass (noun)

A large quantity; a sum.

• Mass (noun)

Large in number.

• Mass (noun)

Bulk; magnitude; body; size.

• Mass (noun)

The principal part; the main body.

• Mass (noun)

A large body of individuals, especially persons.

“The mass of spectators didn’t see the infraction on the field.”

“A mass of ships converged on the beaches of Dunkirk.”

• Mass (noun)

The Eucharist, now especially in Roman Catholicism.

• Mass (noun)

Celebration of the Eucharist.

• Mass (noun)

The Eucharist.

• Mass (noun)

A musical setting of parts of the mass.

• Mass (verb)

To form or collect into a mass; to form into a collective body; to bring together into masses; to assemble.

• Mass (verb)

To have a certain mass.

“I mass 70 kilograms”

• Mass (verb)

To celebrate mass.

Involving a mass of things; concerning a large quantity or number.

“There is evidence of mass extinctions in the distant past.”

Involving a mass of people; of, for, or by the masses.

“Mass unemployment resulted from the financial collapse.”

• Weight (noun)

The force on an object due to the gravitational attraction between it and the Earth (or whatever astronomical object it is primarily influenced by).

• Weight (noun)

An object used to make something heavier.

• Weight (noun)

A standardized block of metal used in a balance to measure the mass of another object.

• Weight (noun)

Importance or influence.

• Weight (noun)

A disc of iron, dumbbell, or barbell used for training the muscles.

“He’s working out with weights.”

• Weight (noun)

Mass (net weight, atomic weight, molecular weight, troy weight, carat weight, etc.).

• Weight (noun)

A variable which multiplies a value for ease of statistical manipulation.

• Weight (noun)

The smallest cardinality of a base.

• Weight (noun)

The boldness of a font; the relative thickness of its strokes.

• Weight (noun)

The relative thickness of a drawn rule or painted brushstroke, line weight.

• Weight (noun)

The illusion of mass.

• Weight (noun)

The thickness and opacity of paint.

• Weight (noun)

Pressure; burden.

“the weight of care or business”

• Weight (noun)

The resistance against which a machine acts, as opposed to the power which moves it.

• Weight (noun)

Shipments of (often illegal) drugs.

“He was pushing weight.”

• Weight (verb)

To add weight to something; to make something heavier.

• Weight (verb)

To load, burden or oppress someone.

• Weight (verb)

To assign weights to individual statistics.

• Weight (verb)

To bias something; to slant.

• Weight (verb)

To handicap a horse with a specified weight.

• Weight (verb)

To give a certain amount of force to a throw, kick, hit, etc.

Wiktionary
• Mass (noun)

the celebration of the Christian Eucharist, especially in the Roman Catholic Church

“we went to Mass”

• Mass (noun)

a particular celebration of the Eucharist

“he pontificated at three Christmas Masses”

• Mass (noun)

a musical setting of parts of the liturgy used in the Mass

“Bach’s B minor Mass”

involving or affecting large numbers of people or things

“a mass exodus of refugees”

“the film has mass appeal”

• Mass (verb)

assemble or cause to assemble into a single body or mass

“both countries began massing troops in the region”

“clouds massed heavily on the horizon”

Oxford Dictionary