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Dynamics - Coggle Diagram
Dynamics
Newton's Laws of Motion
Second law: the rate of change of momentum of a body is proportional to the resultant force and occurs in the direction of force; F = ma
Third law: if a body A exerts a force on a body B, then body B exerts an equal but an opposite force on body A, forming an action-reaction pair
First law: if a body is at rest it remains at rest or if it is in motion it moves with a uniform velocity until it is acted on by resultant force or torque
Momentum
Linear momentum: product of mass and velocity, p = mv
Force: rate of change of momentum, F = (mv - mu) / t
Principle of conservation of linear momentum: when bodies in a system interact, total momentum remains constant provided no external force acts on the system, mAuA + mBuB = mAvA + mBvB
Inelastic Collision
relative speed of approach > relative speed of separation, total momentum is conserved
perfectly inelastic collision: only momentum is conserved, and the particles stick together after collision(i.e. move with the same velocity)
in elastic collisions, total energy is conserved but Ek may be converted into other forms of energy e.g. heat
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Mass and Weight
Mass: is a measure of the amount of matter in a body and is the property of a body which resists change in motion, measured in kilograms, scalar quantity, constant throughout the universe
Weight: is the force of gravitational attraction (exerted by the earth)on a body, measured in newtons, vector quantity, not constant, W = mg
Elastic Collisions
total momentum conserved, total kinetic energy is conserved
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