# Mass

Cast iron weight used for balances – Mass: 2 kg (4.44 lb) Height: 4.9 cm (1.9 in); Width: 9.2 cm (3.6 in)

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.[1] An 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.

## Phenomena

There are several distinct phenomena which can be used to measure mass. Although some theorists have speculated that some of these phenomena could be independent of each other,[2] current experiments have found no difference in results regardless of how it is measured:

• Inertial mass measures an object's resistance to being accelerated by a force (represented by the relationship F = ma).
• Active gravitational mass measures the gravitational force exerted by an object.
• Passive gravitational mass measures the gravitational force exerted on an object in a known gravitational field.

The mass of an object determines its acceleration in the presence of an applied force. The inertia and the inertial mass describe the same properties of physical bodies at the qualitative and quantitative level respectively, by other words, the mass quantitatively describes the inertia. According to Newton's second law of motion, if a body of fixed mass m is subjected to a single force F, its acceleration a is given by F/m. A body's mass also determines the degree to which it generates or is affected by a gravitational field. If a first body of mass mA is placed at a distance r (center of mass to center of mass) from a second body of mass mB, each body is subject to an attractive force Fg = GmAmB/r2, where G = 6.67×10−11 N kg−2 m2 is the "universal gravitational constant". This is sometimes referred to as gravitational mass.[note 1] Repeated experiments since the 17th century have demonstrated that inertial and gravitational mass are identical; since 1915, this observation has been entailed a priori in the equivalence principle of general relativity.

Other Languages
Afrikaans: Massa
Alemannisch: Masse (Physik)
አማርኛ: ግዝፈት
العربية: كتلة
aragonés: Masa
অসমীয়া: ভৰ
asturianu: Masa
Avañe'ẽ: Mba'era'ã
বাংলা: ভর
Bân-lâm-gú: Chit-liōng
башҡортса: Масса
беларуская: Маса
беларуская (тарашкевіца)‎: Маса
български: Маса
Boarisch: Massn
bosanski: Masa
brezhoneg: Mas
буряад: Масса
català: Massa
čeština: Hmotnost
chiShona: Huremu
Cymraeg: Màs
eesti: Mass
Ελληνικά: Μάζα
español: Masa
Esperanto: Maso
estremeñu: Massa
euskara: Masa
Fiji Hindi: Mass
français: Masse
Gaeilge: Mais
Gaelg: Glout
galego: Masa

ગુજરાતી: દ્રવ્યમાન

한국어: 질량
հայերեն: Զանգված
हिन्दी: द्रव्यमान
hrvatski: Masa
Ido: Maso
Ilokano: Masa
Bahasa Indonesia: Massa
íslenska: Massi
italiano: Massa (fisica)
עברית: מסה
Jawa: Massa
Kabɩyɛ: Hɩlɩmɩyɛ
ქართული: მასა
қазақша: Масса
Kiswahili: Masi
Kreyòl ayisyen: Mas inèsi
kurdî: Bariste
Кыргызча: Масса
Latina: Massa
latviešu: Masa
Lëtzebuergesch: Mass (Physik)
lietuvių: Masė
Limburgs: Massa
lingála: Libóndó
Lingua Franca Nova: Masa
lumbaart: Massa
magyar: Tömeg
македонски: Маса (физика)
മലയാളം: പിണ്ഡം
मराठी: वस्तुमान
مصرى: كتله
Bahasa Melayu: Jisim
Mìng-dĕ̤ng-ngṳ̄: Cék-liông
монгол: Масс
မြန်မာဘာသာ: ဒြပ်ထု
नेपाली: पिण्ड

Nordfriisk: Mase
norsk: Masse
norsk nynorsk: Masse
Novial: Mase
occitan: Massa
oʻzbekcha/ўзбекча: Massa
ਪੰਜਾਬੀ: ਪੁੰਜ
پنجابی: وزن
Patois: Mas
ភាសាខ្មែរ: ម៉ាស
Piemontèis: Massa (fìsica)
Plattdüütsch: Masse (Physik)
português: Massa
Ripoarisch: Masse
română: Masă
Runa Simi: Wisnu
русиньскый: Маса
русский: Масса
Scots: Mass
Seeltersk: Masse
shqip: Masa
sicilianu: Massa
සිංහල: ස්කන්ධය
Simple English: Mass
slovenčina: Hmotnosť
slovenščina: Masa
ślůnski: Masa
Soomaaliga: Cuf
کوردی: بارستە
српски / srpski: Маса
srpskohrvatski / српскохрватски: Masa
Basa Sunda: Massa
suomi: Massa
svenska: Massa
Tagalog: Masa
தமிழ்: திணிவு
Taqbaylit: Takura
татарча/tatarça: Massa
తెలుగు: ద్రవ్యరాశి
ไทย: มวล
тоҷикӣ: Масса
Türkçe: Kütle
українська: Маса
اردو: کمیت
vèneto: Masa
Tiếng Việt: Khối lượng

Winaray: Masa

ייִדיש: מאסע