Mechanics. definitions Flashcards
Displacement
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(s)
Distance travelled in a particular direction (change in position)
Velocity
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(u,v)
Rate of change of displacement
Speed
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(u,v)
Rate of change of distance
Acceleration
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(a)
Rate of change of velocity
Newton’s First Law of Motion
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An object at rest remains at rest and and object in motion remains in motion at a constant speed in a straight line unless acted on by an unbalanced force
Newton’s Second Law of Motion
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An unbalanced force will cause an object to accelerate in the direction of the net force. The acceleration of the object is proportional to the net force and inversely proportional to its mass
Fnet=ma
Fnet=∆p/∆t (rate of change in momentum)
Translational Equilibrium
Net force acting on body is zero
Newton’s Third law of Motion
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When two bodies A and B interact (push or pull), the force that A exerts on B is equal and opposite to the force that B exerts on A.
Linear Momentum
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(p)
Product of mass and velocity
Impulse
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(J)
Change in Momentum
Law of Conservation of Linear Momentum
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Total momentum of an isolated system (no external forces) remains constant
Work
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(W)
Product of a force on an object and the displacement of the object in the direction of the force
Kinetic Energy
Ek
Product of 1/2 times the mass of an object times the square of an object’s speed
Change in Gravitational Potential Energy
Product of an object’s mass times the Gravitational field strength times the change in height
Principle of Conservation of Energy
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Total energy of an isolated system (no external forces) remains constant
