questions and solutions
Vector quantities - answershave magnitude and direction
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Examples of vector quantities - answersforce, velocity, momentum, accelerationwu wu wu wu wu wu wu wu
Scalar quantities - answersOnly have magnitude and no direction
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Examples of scalar quantities - answersspeed, distance, time wu wu wu wu wu wu wu
Vectors - answersrepresented by an arrow - the length of the arrow shows the magnitude. The direction of the
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arrow shows the direction of the quantity
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A force is - answersa push or pull on an object that is caused by it interacting with something
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when two objects are touching for the force to act, its a .... - answerscontact force
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examples of contact forces - answersfriction, air resistance, tension in ropes. etc
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If the objects do not need to be touching for the force to act, the force is a ...... - answersnon contact force
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examples of non contact forces - answersmagnetic force and gravitational force
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Two effects of gravity - answers- makes all things fall towards the ground
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- gives everything a weight
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What is mass? - answersThe amount of material an object is made of
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It is the same value everywhere
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Measured using a mass balance wu wu wu wu
What is weight? - answersThe force acting on an object due to gravity
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It depends on the strength of the gravitational field at the location of the object
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Measured using a calibrated spring balance - newtonmeter wu wu wu wu wu wu wu
Equation for Weight - answersWeight (N) = Mass (kg) x Gravitational Field Strength (N/kg)
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W=mg
What is weight directly proportional to? - answersmass
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What are free body diagrams? - answersDiagrams that show all the forces acting on an object
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What is the resultant force? - answersThe single force that replaces multiple forces acting at a single point
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, How is work done? - answersWhen a force moves an object through a distance, energy is transferred and work is
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done on the object
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Equation for 'Work Done' - answersWork done (J) = Force (N) x Distance (m)
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W=Fs
What is 1J equal to? - answers1Nm wu wu wu wu wu wu
If all the forces acting on an object combine to give a resultant force of zero then the object is in ? -
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answersequilibrium
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What could happen when you apply a force to an object? - answersIt may stretch, compress or bend
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What happens when an object is elastically deformed - answersThe object can go back to its original shape and
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length after the force has been removed
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What happens when an object is inelastically deformed? - answersThe object won't return to its original shape and
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length after the force has been removed
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Equation for Force 1 - answersForce (N) = Spring Constant (N/m) x Extension (m)
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F=ke
Extension is directly proportional to? (Hooke's Law) - answersThe force applied
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F∝e
What is the limit of proportionality? - answersThe point at which extension is no longer directly proportional to force
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Practical: Investigating the link between force and extension - answers- First, measure the original length of the
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spring using a milimetre ruler
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- Next, add different masses on the spring and measure the length of the spring in each case.
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- The extension = change in length
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- Repeat this process until you have enough measurements ( no fewer than 6)
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- Plot a graph with extension of the spring on the x axis and force on the y axis.
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- The graph will only start to curve if you exceed the limit of proportionality
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Equation for Elastic potential energy - answersElastic potential energy (J) = 1/2 x Spring Constant (N/m) x
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extension^2 (m)
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Ee = 1/2Ke^2 wu wu
What is displacement? - answersIt measures the distance and direction in a straight line from an object's starting
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point to its finishing point
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What is velocity? - answersSpeed (how fast you're going) in a given direction
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Equation for Speed - answersDistance Travelled (m) = Speed (m/s) x Time (s)
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s=vt
typical speeds - answerstypical speed of a person walking
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1.5m/s