Physics Dictionary Flashcards
Displacement
change in position
Distance
length of path followed
Acceleration
the rate of change of velocity
Instantaneous velocity
the average velocity obtained during an interval of time that is very, very small.
Instantaneous speed
magnitude of the instantaneous velocity
Average speed
total distance travelled divided by the total time taken.
Average velocity
change in position (i.e. the displacement) divided by the time taken
Acceleration of free fall
an acceleration caused by the attraction between the Earth and the body.
Terminal Speed
body moving at constant speed
Weight
the result of the gravitational attraction between the mass m of a body and the mass of the planet on which the body is placed
Tension
The force that arises in any body when it is stretched
Hooke’s Law
The relation between tension and extension
Drag Force
forces that oppose the motion of a body through a lid (a gas or a liquid)
Upthrust
force experienced by any object placed in a fluid
Free-body Diagram
a diagram showing the magnitude and direction of all the forces acting on a chosen body.
Newton’s first law
When the net force on a body is zero, the body will move with constant velocity (which may be zero).
Order of magnitude
an estimate given as just a power of 10
absolute uncertainty
a quantity giving the extremes a measured value falls within
absolute zero
the temperature at which all random motion of molecules stops
absorption spectra
the set of wavelengths of photons absorbed by a substance
albedo
the ratio of scattered to incident intensity of radiation
ammeter
an instrument that measures the electric current through it
angular speed
the ratio of angle turned to time taken
