Flashcards in Paper 1 Vocab Deck (52):

1

## Speed

### Rate of change of distance, speed=distance/time

2

## Velocity

### Rate of change of displacement, velocity=displacement/time

3

## Displacement

### The vector measurement of distance in a certain direction

4

## Vector quantity

### Quantity which has both magnitude and direction

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## Scalar quantity

### Quantity which has only magnitude

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## Average Speed

### The total distance for a journey over the total time taken for the journey

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## Instantaneous Speed

### The speed at any particular instant in time on a journey, which can be found from the gradient of the tangent to a distance-time graph at that time

8

## Acceleration

### The vector defined as the rate of change of velocity

9

## Resultant Force

### The total force/vector sum of forces acting on a body when all the forces acting are added together accounting for their direction

10

## Free-Body force diagram

### Has the object isolated, and all the forces that act on it are drawn in at the points where they act, using arrows

11

## Equilibrium

### There is zero resultant moment. It will have zero acceleration

12

## Principle of Moments

### A body will be in equilibrium if the sum of clockwise moments acting on it is equal to the sum of the anticlockwise moments

13

## Centre of Gravity

### The point through which the weight of an object appears to act

14

## Newton's First Law

### An object will remain at rest, or in a state of uniform motion, until acted upon by a resultant force

15

## Newton's Second law

### If an object's mass is constant, the resultant force needed to cause an acceleration is given by the equation F=ma

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## Newton's Third Law

### For every action there is an equal and opposite reaction

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## Kinematics

### The study of the description of the motion of objects

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## Uniform Motion

### Motion where there is no acceleration

19

## Resolution/Resolving Vectors

### The determination of a pair of vectors, at right angles to each other, that sums to give the single vector they were resolved from

20

## Projectile

### A moving object on which the only force of significance acting is gravity. The trajectory is thus pre-determined by its initial velocity

21

## Gravitational Potential Energy (Ep)

### The energy an object has by virtue of its position in a gravitational field

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## Kinetic Energy (Ek)

### The energy an object has by virtue of its movement

23

## Conservation of Energy

### Requires that energy can never be created or destroyed

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## Work Done

###
The product of a force and the distance moved in the direction of the force

W=Fs

25

## Energy

### The property of an object that gives it the capacity to do work. A change in the amount of energy of an object could be equated to work being done, even if this is not mechanical

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## Power

### Rate of energy transfer

27

## Efficiency

###
The ability of a machine to convert energy usuefully

Efficiency = Useful energy output/ Total energy input

Efficiency = Useful power output/ Total power input

28

## Momentum

###
The measure of an object's motion, given by the equation:

Momentum = mass * velocity, p=mv

29

## Conservation of linear momentum

### The vector sum of momenta of all objects in a system is the same before and after any interaction between the objects provided no external forces are added

30

## Explosion

### A situation in which a stationary object or system of joined objects separates into component parts, which move off at different velocities. Momentum must be conserved in explosions

31

## Charge

### A fundamental property of some particles. It is the cause of the electromagnetic force, and it is a basic aspect of describing electrical effects.

32

## Coulomb

### Unit of charge. One coulomb is the quantity of charge that passes a point in a conductor per second when one ampere of current is flowing in the conductor. The amount of charge on a single electron is -1.6*10^-19C

33

## Current

###
Rate of flow of charge. Current can be calculated from the equation:

Current = Charge passing a point/time for charge to pass

I=Q/t

34

## Ampere

### The movement of 1C of charge per second

35

## Voltage

### A measure of the amount of energy a component transfers per unit of charge

36

## Electromotive Force/emf

### A supply voltage

37

## Potential Difference/pd

### The correct term for voltage for a component that is using electrical energy in a circuit and transferring this energy into other forms

38

## Electronvolt/eV

### The amount of energy an electron gains by passing through a voltage of 1 V, 1 eV=1.6*10^-19

39

## Resistance

### The opposition to the flow of electrical current

40

## Ohm's law

### The current through a component is directly proportional to the voltage across it, providing the temperature remains the same

41

## Resistivity

### The general property of a material to resist the flow of electric current

42

## Drift Velocity

### The slow overall movement of the charges in a current

43

## Transport Equation

### I=nAve, I=Current, n=Number of electrons, A=cross-sectional area, e=Charge on an electron

44

## Semiconductors

### Materials that have a lower resistivity than insulators, but higher than conductors. They usually only have small numbers of delocalised electrons that are free to conduct

45

## Conduction Band

### A range of energy amounts that electrons in a solid material can have which delocalises them to move more freely through the solid

46

## Valence Band

### A range of energy amounts that electrons in a solid material can have which keeps them close to one particular atom

47

## Critical Temperature

### The temperature below which a material's resistivity instantly drops to 0

48

## Kirchhoff's First Law: Electric Current Rule

### The algebraic sum of currents entering a junction is equal to zero

49

## Kirchoff's Second Law: Voltages Circuit Rule

### Around a closed loop, the algebraic sum of the emfs is equal to the algebraic sum of the pds

50

## Potential Divider

### This type of circuit is designed to provide specific voltage values by splitting an emf across two resistors

51

## Potentiometer

### A version of the potential divider in which a single resistance wire is used in two parts to form two resistances. A sliding connection on the wire can be adjusted to alter the comparative resistances and thus alter the output pd from the potentiometer

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