Flashcards
PH4
Cards in this deck (18)
- 1Newton's Second Law of MotionThe rate of change of a body's momentum is proportional to the resultant force acting on it, and the direction of change is that of the resultant force
- 2The principle of conservation of MomentumThe vector sum of the momenta of the bodies in a system is constant, provided there is no resultant force from outside the system
- 3In an Elastic collision...no kinetic energy is lost or gained.
- 4Centripetal AccelerationA body is moving at constant speed around a circular path is accelerating, because its velocity is always changing (in direction)
Centripetal- always directed towards the circle centre - 5Spring ConstantThe force exerted by the spring, per unit extension
- 6Simple Harmonic Motion (SHM)A body performs SHM if its acceleration is proportional to its displacement from a fixed point, but is in the opposite direction to its displacement.
- 7Natural Oscillations occur...when a body on a spring, a pendulum, or any other system with a mass and a force pulling it towards an equilibrium point, is displaced from equilibrium and released.
- 8DampedAmplitude decreases with time due to resistive forces
Periodic time is constant, amplitude falls exponentially - 9Critical DampingDoesn't oscillate if displaced, returns to equilibrium.
- 10MolesA batch of 6.02x10^23 molecules
The number of molecules per mole is called Avogadro's constant - 11Boyle's LawFor a fixed mass of gas at constant temperature, the pressure exerted is inversely proportional to the volume occupied.
pV=constant - 120 KelvinAbsolute zero, -273.2'C
- 13Ideal Gas equationpV=nRT (using temperature in Kelvin)
- 14Kinetic Theory of Gases1. collisions between molecules are elastic
2. molecules occupy negligible fraction of container volume
3. compared to forces exerted on container walls, molecules exert negligible force on each other. - 15ThermodynamicsThe internal energy of a system, and transfers of energy as work and heat into and out of the system
- 16Rapid Expansion of an Ideal GasRapid change doesn't allow time for much heat flow. Q=0, therefore dU=-W
- 17Slow Expansion of an Ideal Gas (Isothermal)Gas temperature will not be able to fall, thus the expansion is isothermal (constant temperature), dU = 0
therefore 0=Q + W
Q = W - 18Specific Heat CapacityThe heat input required to raise the temperature of mass, m, of a solid or liquid by dT.
Q = mcdT
c = SHC (J kg^-1 K^-1)
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- Flashcards on PH4, created by cerysroche on 02/05/2015.
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- cerysroche
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