Definitions Flashcards
Define precision
A measure of how close the results of an experiment agree with each other
Define accuracy
A measure of how close the results of an experiment agree with the true value
Define a random error
Errors of measurements in which the measured quantities differ from the mean value with different magnitudes and directions
Define a systematic error
Errors of measurements in which the measured quantities are displaced from the true value by fixed magnitude and in the same direction
Define homogeneous
units on both sides of the equation are identical
Define velocity
The rate of change of displacement
Define acceleration
The rate of change of velocity
Define the resultant force
A single force upon an object found by adding all the forces acting upon an object
Define the normal contact force
A force perpendicular to the surface experienced by a body when it is in physical contact with something else
Define moment
The product of the force and the perpendicular distance between the axis of rotation and the line of action of the force
Define the centre of gravity of an object
The point on an object through which the entire weight of the object may be considered to act
Define work done
The product of the force and the displacement of the object in the direction of that force
Define gravitational potential energy
the amount of work done in order to raise the body to a height
Define power
The rate of energy transfer
Define stress
The tensile force applied per unit of crossectional area
Define strain
The ratio of change in length and original length of a material
Define young modulus
The ratio of stress and strain
Define the elementary charge
The charge of an electron
Define current
The rate of flow of charge
Define potential difference
The electrical energy converted into other forms of energy per unit charge
Define the electron volt
The energy gained by an electron across a p.d. of one volt
Define the electromotive force
The energy converted from other forms to electrical per unit charge
Define frequency
The number of waves passing a point per unit time
Define displacement
The distance of the oscillating particle from its equilibrium position
Define amplitude
The magnitude of the maximum displacement of the oscillating particle from the equilibrium position
Define phase difference
The difference in rotation in the wave cycle between two points on a wave
Define intensity
The rate of transfer of energy per unit area perpendicular to the direction of travel of the wave
Define work function
The minimum amount of energy necessary to remove a free electron from the surface of the material
Define a photon
A discrete packet of electromagnetic energy
Define internal energy
The sum of the individual random kinetic and potential energies of particles in a substance
Define specific heat capacity
The change in thermal energy per unit mass to change the temperature of the material by 1 K
Define specific latent heat
The energy required per unit mass to change the state of a substance without any temperature change
Define angular displacement
The angle subtended at the centre of a circle by an arc of equal length to the radius
Define angular velocity
The rate of change of angular displacement
Define resonance
When an oscillating system is driven at a frequency which is the same as its natural frequency
Define gravitational field strength
The gravitational force per unit mass acting on a mass placed at that point
Define gravitational potential energy
The work done by an external force in bringing that point mass from infinity to that point
Define gravitational potential
The work done per unit mass, by an external force, in bringing the mass from infinity to that point
Define capacitance
The charge stored per unit potential difference across the capacitor
Define time constant
The time for a capacitor to discharge to 37% of the original charge stored
Define electric field strength
The electrostatic force per unit charge experienced by a positive test charge placed at that point
Define electric potential
The work done per unit charge in bringing a positive test charge from infinity to that particular point without acceleration
Define electrical potential energy
The work done by an external force in bringing the charge from infinity to a point
Define magentic flux
The product of the magnetic flux density normal to the surface and the area of the surface
Define magnetic flux linkage
The product of the number of turns of the coil and the magnetic flux linking each turn
Define activity
The average number of unstable nuclei disintegrating per unit time
Define the decay constant
Probability of decay per unit time
Define the mass defect
The difference between the mass of the separated nucleons and the combined mass of the nucleus
Define attenuation
The reduction in wave intensity as it propagates through a material
Define acoustic impedance
The product of the density of a substance and the speed of the wave through it
