IB Physics

Fundamental unit: A quantity that can be measured in a simpler form, such as metre, kilogram, second, Ampere, Kelvin, mole, radian

Dervied Unit: A unit that is derived from a combination of fundamental units as above. Newton is a derived unit (actually kgm²s^-2), as is hertz, JOULE, watta, telsa, and coulumb, also volt.

Kilogram: The mass of a particular piece of platimnum-iridium alloy that is kept in france.

Metre: The length equal to 1 650 763.73 wavelenths of a particular orange-red line of krypton-86 undergoing electrical discharge.

Second: The time for 9 192 631 770 vibrations of the cesium-133 atom.

Vector: A quantity that has both a magnitude and a direction.

Scalar: A quantity consisting of only magnitude.

Amplitude: The distance between the mean position of a wave and its maximum.

Frequency: The number of waves occurring in a second measured in htz.

Period: The time for one complete wave.

Wavelength:The length of each complete wave.

Random uncertainty: errors due to variations in the performance of the instrument and the operator.

Systematic error: An error that causes a random set of measurements to be spread about a value rather than being spread about the accepted value.

Displacement (s): The measured distance in a given direction.

Velocity (v): Speed in a given direction, measured by m/s

Acceleration: The rate of change of velocity in a given direction, m/s²

Reference frame: A point of reference at which the relative value is taken as 0. In most cases, the earth is used as the reference frame.

Instantaneous velocity: The velocity of an object at exactly a point in time.

Average velocity: The change in displacement divided by a change in time.

Average acceleration: The change in velocity divided by a change in time.

Mass: A measure of the inertia of a body

Weight: The force of gravity acting on a body.