Key Terms and Concepts
- Define mass, volume, density, weight and apparent weight.
- Explain how mass and weight are related when near the surface of Earth and calculate one from the other.[1,2]
- Apply the concept of static equilibrium to determine the magnitude and direction of unknown forces.
- Apply Archimedes’ principle to determine the buoyant force objects and decide if they will sink or float.
- Determine density from mass and volume measurements and via hydrostatic weighing.
a measurement of the amount of matter in an object made by determining its resistance to changes in motion (inertial mass) or the force of gravity applied to it by another known mass from a known distance (gravitational mass). The gravitational mass and an inertial mass appear equal.
a quantity of space, such as the volume within a box or the volume taken up by an object.
relation between the amount of a material and the space it takes up, calculated as mass divided by volume.
the force of gravity on on object, typically in reference to the force of gravity caused by Earth or another celestial body
the reading on a scale that is used to measure the weight of an object that is submerged in a fluid
the state being in equilibrium (no unbalanced forces or torques) and also having no motion
the total amount of remaining unbalanced force on an object
the upward force exerted by any fluid upon a body placed in it
The upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid being displaced by the body
a technique for measuring the mass per unit volume of a living person's body. It is a direct application of Archimedes' principle, that an object displaces its own volume of water
the ratio of the density of a substance to the density of a standard, usually water for a liquid or solid, and air for a gas