Chapter 2: Models, Measurements and Vectors

SI

A system of units known as ________ or International System is used by scientists and engineers all over the world.

physics

________ is a process by which we arrive at general principles that describe the behavior of the universe.

physical quantities

________ are related using equations.

uncertainty

________ or error of a measured value is an indication of the maximum difference there is likely to be between a measured value and the true value.

significant figures

________ are the meaningful digits in a measured value that tell us which digits are reliably known and which digit is uncertain.

operational definition

A(n) ________ is a procedure for measuring a fundamental quantity that serves as its definition.

physical quantity

A(n) ________ is a number used to describe an observation of a physical phenomenon quantitatively.

quantities

________ are measured by comparing them with a reference standard known as a unit.

accuracy

________ is the degree of closeness of a measured value to the true value.

International Bureau of Weights

A kilogram is the mass of a particular cylinder of platinum- iridium alloy kept at the ________ and measures.

standard SI prefixes

The ________ represent multiples and submultiples of 10 of the units they precede.

order of magnitude calculation

A(n) ________ is a rough, crude estimate which is designed to be accurate within a factor (usually) of 10.

physical quantities

A unit is a reference standard with which ________ are compared.

second

Time is measured in ________

second

The time required for 9,192,631,770 oscillations of Cesium 133 atom.

meter

Length is measured in ________

meter

The distance travelled by light (in a vacuum) in 1/299,792,458 seconds.

prefixes

Larger and smaller units of a predefined physical quantity are introduced using ______

significant figures

________ are the meaningful digits that tell us which digits are reliably known and which digit is uncertain.

vector

A quantity that has both magnitude and direction.

The x-component of a vector A

Aₓ=Acosθ

The y-component of a vector A

Aᵧ=Asinθ