Physics-mechanics

Vector
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Terms in this set (38)
Vector
A quantity that has magnitude and direction
Scalar
A quantity that has only magnitude
Newton's First Law
A body continues in a state of rest or uniform motion unless a resultant external force acts on it.
Friction
A force that opposes the relative motion of 2 objects in contact.
Inertia
A refusal to change their state of motion.
Newton's Second Law
The rate of change of the momentum of the body is proportional to this force.
Mass
A measure of its inertia
Weight
The force of gravity acting on the body
Momentum
mass x velocity
Acceleration
Final velocity minus initial velocity over Time.
DisplacementDistance in a given directionSpeeddistance over timeVelocitydisplacement over timeterminal velocitythe constant velocity of a falling object when the force of air resistance is equal in magnitude and opposite in direction to the force of gravityNewton's Third LawFor every action there is an equal and opposite reaction Action and reaction do not happen on the same bodyconservation of momentumWhen 2 or more bodies interact in a CLOSED SYSTEM, the total momentum of the 2 bodies before the interaction equals the total momentum of the bodies after the interaction.workForce times displacementEnergythe ability to do work, measured in joulesconservation of energyEnergy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changeskinetic energyenergy due to motionpotential energystored energy that results from the position or shape of an objectPowerthe rate at which work is done, measured in watts.pressureForce per unit area. Unit is pascal.Densitymass over volumeArchimedes' PrincipleWhen an object is immersed in a fluid it will experience an upthrust equal in magnitude to the weight of the fluid displaced.Law of floatationWhen an object floats the weight of the object in air equals the weight of the fluid displacedhydrometeran instrument for measuring the density of liquids.Boyle's LawFor a fixed mass of gas at a fixed temperature the pressure of the gas is inversely proportional to the volume of the gas.Moment of a forceForce x perpendicular distance from pivotLaw of EquilibriumA body is in equilibrium if the vector sum of the forces in any direction on the body is zero and the sum of the moment of the forces about any point on the body is zero.The periodic timeThe time taken for one full circular motion.centripetal accelerationAcceleration acting towards the centre of a circle for an object undergoing uniform circular motioncentripetal forcea force that acts on a body moving in a circular path and is directed toward the center around which the body is moving.Newton's Law of Universal GravitationAny 2 point masses in the universe attract each other with a force that is directly proportional to the product of the masses and inversely proportional to the square of the distance between the point masses.geostationary satellitesGeostationary satellites give the illusion of being stationary above a particular point on the earth. To an observer on earth it seems that the satellite is always in the same place.Speed of a satelliteGravitational force between satellite and earth = centripetal force keeping satellite in orbit around planet.simple harmonic motionThe motion of an object whose acceleration is proportional to its displacement from a fixed point. The direction of acceleration is opposite to the direction of displacementleverA simple machine that consists of a rigid body which is free to rotate about a fixed point called an axis or a fulcrum. A lever may be used to amplify a force.