Year 13 physics definitions topic order Flashcards
Absolute or thermodynamic temperature scale
An absolute or thermodynamic temperature scale is independent of the proerties of any specific substance. It is measured in Kelvin, K.
Absolute zero
Absolute zero (0 K) is the temperature at which a substance has minimum internal energy; this is the lowest limit for temperature.
Thermal equilibrium
Thermal equilibrium occurs when two objects are in contact with each other and are the same temperature; this means there is no net heat flow between them.
The kinetic model of matter
The kinetic model of matter is where all matter is made of very small particles (atoms, molecules or ions) which are in constant motion
Internal energy
Internal energy is the sum of the kinetic and potential energies of all the atoms or molecules within a system.
Brownian motion
Brownian motion is the random movement of small visible particles suspended in a fluid due to collisions with much smaller, randomly moving atoms or molecules of the fluid.
Specific heat capacity
Specific heat capacity of a substance is the energy needed to raise the temperature of 1 kg of the substance by 1 K.
Specific latent heat of fusion.
Specific latent heat of fusion of a substance is the energy needed to change the phase of 1 kg of the substance from solid to liquid.
Specific latent heat of vaporisation.
Specific latent heat of vaporisation of a substance is the energy needed to change the phase of 1 kg of the substance from liquid to gas.
The mole.
A mole of a substance will contain 6.02 x 1023 particles. This number is called Avagadro’s constant.
The relative atomic mass of a substance in g, contains 1 mole of particles.
An ideal gas
An ideal gas is one that has internal energy only in the form of random kinetic energy.
Boyle’s Law
Boyle’s Law states that the volume of a fixed mass of gas is inversely proprtional to the pressure exerted on the gas, under conditions of constant temperature.
PV = constant
Radian
One radian is the angle subtended at the centre of a circle by an arc equal in length to the radius subtended.
Period
Period is the time needed for one complete cycle of vibration to pass a given point or for one complete revolution incircular motion.
Angular velocity
Angular velocity is the rate of angular rotation, measure in radians per second.
Centripetal acceleration
Centripetal acceleration is the acceleration of an object moving with uniform circular motion.
It is directed radially inwards towards the centre of the circle, perpendicular to the velocity vector at any instant.
Centripetal force
Centripetal force is the resultant force on an object causing it to move in a circular path, and is directed towards the centre of the circle.
Displacement (SHM)
Displacement (SHM) is the distance an object is from its equilibrium position. It may be + or -.
Amplitude (SHM)
Amplitude (SHM) is the maximum displacement.
Frequency (SHM)
Frequency (SHM) is the number of oscillations per second at any point.
Isochronous
Isochronous oscillations have a constant time period. All SHM oscillations are isochronous even though the amplitude might decrease due to damping.
Simple harmonic motion
SHM occurs when the acceleration is directly proportional to the displacement from a fixed point, and always directed towards that point.
Damping
Damping forces reduce the amplitude of an oscillation over time due to energy being removed from the system.
Resonance
Resonance occurs when the driving frequency equals the natural frequency of the system being forced to oscillate. This results in the body vibrating at its natural frequency and maximum amplitude.
Free oscillations
Free oscillations occur when there is no external periodic force. The system oscillates at its natural frequency.
Natural frequency
Natural frequency is the frequency at which a system will oscillate when undergoing free oscillations.
Forced oscillations
Forced oscillations occur when an external or driving force is applied to keep the body oscillating. The system oscillates at the frequency of the driving force.
Driving frequency
Driving frequency is the frequency of the driving force applied to an oscillating object.
Gravitational field
Gravitational field is the region around a body in which other bodies will feel a force due to the mass of the body.
Gravitational field strength
Gravitational field strength is the force acting per unit mass at that point.
Newton’s law of gravitation
Newton’s law of gravitation states that a particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.
Kepler’s third law
Kepler’s third law states that the square of the period of a planet orbiting the Sun is proportional to the radius of its orbit cubed.
Geostationary orbit
Geostationary orbit is one which has the same time period and orbital direction as the rotation of the Earth (i.e. 24 hours) and is in the equatorial plane.
Gravitational potential
Gravitational potential at a point in a gravitational field is defined as the work done in moving unit mass from infinity (where gravitational potential is zero) to that point.
Gravitational potential energy
Gravitational potential energy of a mass m in a radial gravitational field caused by mass M a distance r from M is given by -GMm/r
