Physics p1-4
- Created by: mwoodier123
- Created on: 19-05-19 17:13
P1 Matter=Energy=(J)=depends on arrangement and speed of particles.Temp=average kinetic energy the particles have.Specific heat capacity=energy needed to raise temp of 1kg of substance by 1K.SHC&SLH=energy changes for ikg of a substance.SLH=change of state,SHC=change of temp.Model of Earth's atmosphere=scienctists assume density is the same everywhere.Small thickness compared with diameter of Earth.Earth's atmos pressure=101325 Pa.Changes with height=pressure at bottom is gretaer.
P2 Forces=Vector=has magnitude (size) and direction e.g.force.Length of arrow=magnitude.Direction of arrow=direction.Scalar=magnitude but no direction.Acceleration=change in velocity per second.Gravitational interaction between you and Earth produces same magnitude (size) force on both you and the Earth.Pairs of forces arise when objects interact.Non-contact=arise as charges,magnets masses interact at a distance.E.g gravity.Contact=solid surfaces an exert a force on objects that exert a force on them.E.g.upthrust on a floating boat.Newton's 3rd law=For every action there is an equal and opposite reaction.Shape of a force-extension graph for a spring=straight line up to a certain point-linear relationship up to this point-limit of proportionality.Below elastic limit-returns to original length.Above is deformed.Linear extension&elastic deformation=below elastic limit.Non-linear extension and pastic dformation-above elastic limit.Gradient of a force-extension graph before elastic limit=spring constant.Acceleration due to gravity is 10 m/s2 on Earth.9.81m/s2/9.81 N/Kg.Forces cause a rotation=lean back on somthing e.g. a chair==legs act as pivot.Force acting when you lean back-certain distance from pivot,chairs turns-moment.Difficult to produce turning effect-force acts closer to pivot.Levers=force multiplier.Transmits forces by rotating about a pivort.Effort is force that you exert on lever.Load is force lever exerts on load.Pivot close to load-small effort to lift.Pushing down-turning force on load,hands moves further than load.Ratio of load to effort-mechanical advantage.Gears=levers that rotate.Can change direction.If you make small cog rotate,certain force,larger cog rotates.Bigger cog=bigger force.Ratio of diameters=effort&load.Fill bag with water-water leaves bag at ninety degrees to surface pressure produces force at right angles to any surface.Hydralic machines=2 pistons connected by pipe.Push on…
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