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# G484

Term | Definition |
---|---|

linear momentum | the product of mass and velocity and appreciate the vector nature of momentum |

Newtons Second Law of motion | The net force acting on an object is directly proportional to the rate of change of momentum of that object. |

Impulse of force | Area under a force against time graph (Force * time) Equal to the change in momentum |

perfectly elastic collision and an inelastic collision | Perfectly elastic - Momentum and kinetic energy conserved Inelastic - only momentum is connserved |

the principle of conservation of momentum | Within a closed system, the total momentum in any specific direction remains constant. |

radian | One radian is the angles subtended at the centre of a circle by an arc of length equal to its radius of the circle. |

gravitational field strength | The gravitational field strength at a point is the gravitational force exerted per uni mass on a small object placed at that point. |

Newton’s law of gravitation | Any 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. |

geostationary orbit | A satellite which remains at a fixed point above earth and orbits at the same rate as earth |

internal energy | The sum of the random distribution of kinetic and potential energies associated with the molecules of it's atoms or molocules |

specific heat capacity | The specific heat capacity of a substance is the energy required per unit mass of the substance to raise the temperature by 1 k (1 degree) |

Boyle’s law; | The pressure exerted by a fixed mass of gas is inversely proportional to its volume, provided the temperature of the gas remains constant |

Charles Law | v directly proportion to T (V/T =k) |

Pressure Law | P directly proportional to T |

Newtons First Law | An object will remain at rest or keep travelling at constant velocity unless it is acted on by an external force. |

Newtons Third Law | When two bodies interact, the forces they exert on each other are equal in magnitude and opposite in direction. |

Kepler's third law | The square of the period T of a planet is directly proportional to the cube of the distance r from the sun T^2 -P to r^3 |

SHM, A= | A=-W^2Acos(WT) |

Omega= | 2.pi.f |

(SHM) x= | Acos(WT) |

(SHM) V= | -WAsin(WT) |

What is resonance? | Resonance is the phenomenon that occurs when a physical system is periodically disturbed at the same period of one of its natural frequencies. Occurs when driving frequency = natural frequency |

Circular motion v= a= | 2.pi.r/T v^2/r |

When will a object travel in a circular path? | When there is a force perpendicular to the objects velocity |

Uses of resonance | Cooking - the water molocules forced to vibrate and they absorb energy of microwave radiation. The water gets hotter and the absorbed energy spreads through the food and heats it. Bridge |

Random motion aka | Brownian motion |

Assumptions for ideal gases | Collisions with other particles are perfectly elastic There are a very large number of particles involved the time of a collision is negligible compared to time between collisions |

Assumptions for ideal gases | The volume occupied by the particles is negligible compared to volume of container Particles are involved in random motion |

The energy required to change a solid into a liquid at a constant temperature | Latent heat of fusion |

A liquid into a gas at constant temperature | Latent heat of vaporisation |

SHM | Force/acceleration is proportional to displacement (from equilibrium position) (Resultant force) force/acceleration is (always) towards equilibrium position (WTTE, e.g. allow fixed point). |

POWER | Energy/time |

For any system in resonance | Its natural frequency is equal to frequency of driver Its amplitude is maximum It absorbs max energy |

Why does circular motion no change in speed | Resultant force (F) acts at 90o to motion Fcos90 =0 |

Potential and kinetic energy changes as tmeperature and state changes | As temperature rise, KE increases, very small PE increase, at constant temp, no change in KE however large PE. |