G484 Definitions Flashcards
State the principle of conservation of momentum
Within a closed system, the total momentum in any specified direction remains constant.
Define what is meant by a perfectly elastic collision
In a perfectly elastic collision, momentum, kinetic energy and total energy are all conserved.
Define linear momentum
Momentum = Mass x velocity
Define what is meant by an Inelastic collision
In an Inelastic collision, both momentum and total energy are conserved but the kinetic energy is not conserved as its transformed to other types of energy
Define Newton’s law of gravitation
Two point masses attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of their separation.
Define Kepler’s third law of planetary motion
The square of the period T of a planet is directly proportional to the cube of its distance r from the sun.
Define gravitational field strength
The gravitational force exerted per unit mass on an object at a point within the field.
Define orbital period of a satellite
The time taken for one orbit.
Define geostationary orbit
The orbit of an artificial satellite which has a period equal to one day, and is in the same direction as planetary rotation, so the satellite remains over the same point on the Earth’s equator.
Define Free Oscillation
The natural oscillation of an object after an initial disturbance
Define Forced Oscillation
The oscillation of an object due to a driving frequency
Define Natural Frequency
The frequency at which an object oscillates freely
Define Oscialltion
The repeated movement of an object back and forth about an equilibrium
Define Amplitude
The maximum displacement of an oscillation
Define Period
The time taken for one complete oscillation
Define Frequency
The Number of full oscillations per unit time
Define Phase Difference
The difference in Phase between two oscillations with the same frequency, measured in Radians
Define Simple Harmonic Motion (S.h.m)
A type of oscillation for which the mass always accelerates towards the equilibrium at a rate directly proportional to it’s displacement at that point.
What unit does impulse have?
Ns or kgms-1
The two forces cause by Newton’s 3rd law must…
Act on different bodies
Be equal in magnitude
Be opposite in direction
Be of the same type
What is a special case of Newton’s second law where mass remains constant?
F=ma
Which part of a force against time graph shows impulse?
The area under the graph
Impulse =
The change of momentum
What is Newtons third Law?
When two bodies interact, the forces they exert on each other are equal and opposite
What is Newton’s second Law?
The net force acting on an object is equal to the rate of change of linear momentum of the object. The net force and change in momentum are in the same direction
What is Newton’s first Law?
An object will remain at rest or remain at constant velocity, unless it is acted upon by an external force
Define the period
The time taken for one complete oscillation
Define centripetal acceleration
The acceleration towards the centre of the circle that holds the object in elliptical orbit a=v²/r
Define centripetal force
The net force acting on an object describing a circular path. It is always directed towards the centre of the circle
Define the radian
One radian is the angle subtended at the centre of a circle by an arc of length equal to the radius of the circle
Define specific latent heat
The energy required per kilogram of the substance to change its state without a change in temperature
Define specific heat capacity
Energy supplied
______________________
Mass x Temperature change
Define specific latent heat of vaporisation
The energy required to boil a substance at constant temperature
Define latent heat of fusion
The energy required to melt a substance at constant temperature
Define internal energy
The sum of the random distribution of kinetic and potential energies of molecules in a closed system
State the relationship between the temperature and kinetic energy of an atom
The mean kinetic energy of an atom of an ideal gas is proportional to the thermodynamic temperature.
State Charles’ law
For a constant pressure, the volume is directly proportional to the temperature of the gas
State Boyle’s law
The pressure exerted by a fixed mass of gas is inversely proportional to its volume, as long as temperature is constant
Define a mole of a substance
One mole of any substance is the amount of that substance that contains the same number of particles as there are in 12g of carbon 12
What is a damped oscillation?
An oscillatory motion where the amplitude decreases with tme due to energy loses
What is resonance?
Resonance is when the forced motion acting on an oscillator has a frequency which matches the oscillators natural frequency.
