# Mass FAQs:

Q: Are mass both a property of a physical body and a measure of its resistance to acceleration when a net force is applied?

A: Yes.

Q: Are mass a measure of an object's resistance to acceleration when a force is applied?

A: Yes.

Q: Are mass converted to energy?

A: Yes, or vice versa.

Q: Are mass not the same as weight?

A: Yes, and 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.

Q: Are mass strongly related to the gravitational interaction but a theory of the latter has not been yet reconciled with the currently popular model of particle physics?

A: Yes, and known as the Standard Model.

Q: Are mass the property that determines the strength of this force?

A: Yes.

Q: Are mass the total quantity of energy in a body or system divided by c2?

A: Yes.

Q: Are mass identical?

A: Yes, since 1915, this observation has been entailed a priori in the equivalence principle of general relativity.

Q: Are mass zero?

A: Yes, and hence no concept of a particle can be attributed to it.

Q: Are mass not quantized?

A: Yes.

Q: Are mass proportional to the energy?

A: Yes, and it has gradually fallen into disuse among physicists.

Q: Are mass determined by dividing an object's weight by its free-fall acceleration?

A: Yes.

Q: Are mass that it fails to take into account the potential energy needed to bring two masses sufficiently close to one another to perform the measurement of mass?

A: Yes.

Q: Are mass slightly different than the definition in the theory of special relativity?

A: Yes, but the essential meaning is the same.

Q: Are mass one of the irreducible representation labels of the PoincarĂ© group?

A: Yes.

Q: Are mass associated with matter?

A: Yes, although matter is not, ultimately, as clearly defined a concept as mass.

Q: Are mass accelerated away from free fall?

A: Yes.

Q: Are mass a measure of the strength of an object's gravitational flux?

A: Yes, Gravitational field can be measured by allowing a small "test object" to fall freely and measuring its free-fall acceleration.

Q: Are mass conceptually distinct?

A: Yes, and no experiment has ever unambiguously demonstrated any difference between them.

Q: Are mass groundbreaking partly because it introduced universal gravitational mass: every object has gravitational mass?

A: Yes, and therefore, every object generates a gravitational field.

Q: Are mass the kilogram?

A: Yes, The kilogram is 1000 grams , first defined in 1795 as one cubic decimeter of water at the melting point of ice.

Q: Are masses determined by weighing?

A: Yes.

Q: Are mass conserved in any given frame of reference?

A: Yes.

Q: Are mass the mass of an object measured by its resistance to acceleration?

A: Yes.

Q: Are mass the Newtonian mass as measured by an observer moving along with the object?

A: Yes.

Q: Are mass known to over nine significant figures?

A: Yes.

Q: Are masses sometimes referred to as the "Galilean equivalence principle" or the "weak equivalence principle"?

A: Yes, The most important consequence of this equivalence principle applies to freely falling objects.

Q: Are mass the number describing under which the representation of the little group of the PoincarĂ© group a particle transforms?

A: Yes.

Q: Are mass a measure of the strength of an object's interaction with a gravitational field?

A: Yes.