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Momentum and Energy
Quick Introduction
Question | Answer |
---|---|
Collision – elastic | a collision that conserves kinetic energy and momentum |
Collision – inelastic | a collision the some kinetic energy is changed into heat, light, sound, deformations...; momentum still conserved |
Conservation of p | the sum of all momenta of the particles of a system is unchanged after an event (explosion or collision) |
Energy | the ability to make changes |
Energy | a condition of an object or system of objects; scalar quantities (no direction); unit in Joules; 1 J = 1 N-m = 1 kg-m2/sec2 |
Energy – gravitational | gravitational potential energy is energy stored in an object-earth system because work was done “against” gravity |
Energy – potential | “Stored” energy; energy created because a force “acted” through a distance; stored in a system of objects |
Energy – types | kinetic, gravitational potential, heat, light, sound, electromagnetic radiation, high speed particles, etc. |
Energy – Work | a transformation mechanism for changing one mechanical energy into another (kinetic to potential) or to heat |
Energy – Work theorem | The change in kinetic energy is due to the work done on a moving object |
Impulse | change in momentum (change in p) |
Impulse – due to force | change in momentum due to a force “acting” for a time period |
Momentum | “quantity of motion”; vector quantity; one of the properties of matter |
Newton’s 3rd Law | the change in p of one object during an interaction equals the change in p of the other object except in opposite direction |
Power | Rate of work being done; units are “watts” 1 watt = 1 Joule/sec = 1 kg-m^2/sec^2 |