CIE 9702 Physics AS Definitions List

1. Base unit - stand alone units from which other units are derived
2. Derived unit - products or quotients of the base units
3. Scalar quantity - quantity that has magnitude only
4. Vector quantity - quantity that has magnitude and direction
5. Systematic error - error that causes the readings to have a constant deviation from either side of the actual reading.
6. Random error - error that causes the readings to scatter around the mean value
7. Distance is the total path traveled.
8. Displacement is the shortest distance between a start point and an end point.
9. Speed is total distance traveled divided by time taken
10. Velocity - rate of change of displacement
11. Acceleration - rate of change of velocity
12. Mass - property of a body resisting changes in motion
13. Mass - quantity of matter in a body
14. Newton's 1st Law - A body continues at rest or constant velocity unless acted upon by a resultant force
15. Newton's 2nd Law - The rate of change of momentum is proportional to the resultant force and it occurs in the same direction as the force.
16. Newton's 3rd Law - If body A exerts a force on body B, body B exerts a force of equal magnitude on body A but opposite in direction.
17. Momentum - product of mass and velocity
18. Principle of conservation of momentum - total momentum of an isolated system of bodies is constant
19. Force - rate of change of momentum
20. Conditions for equilibrium - zero resultant force in any direction, zero resultant moment about any point
21. Centre of gravity - The point on a body where weight of the object is considered to act on
22. Moment - force x perpendicular distance from the point of moment to the line of action of the force
23. Couple - a pair of parallel forces that are equal in magnitude but opposite in direction, and they are not in line.
24. Torque - product of one of the force of a couple and the perpendicular distance between the pair of forces 
25. Work done - force x distance moved in the direction of the force
26. Energy - the ability to do work
27. Power the rate of work done
28. Kinetic energy - energy an object has due to its motion
29. Gravitational potential energy - energy a mass stored due to its position in a gravitational field
30. Elastic potential energy - energy store in a body due to its deformation
31. Efficiency - useful output power divided by input power
32. Density - mass divided by volume
33. Pressure - force x area normal to the force
34. Hooke's Law - extension is directly proportional to the force, provided that the proportionality limit is not exceeded
35. Stress - force per unit cross-sectional area
36. Strain - change in length per unit original length
37. Young modulus - stress divided by strain
38. Amplitude - maximum displacement from equilibrium position
39. Wavelength - minimum distance between two points having the same displacement and moving in the same direction
40. Wavelength - distance between two adjacent wavefronts
41. Wavelength - distance moved by a wavefront during one period
42. Frequency - number of oscillations per unit time
43. Frequency - number of wavefronts passing through a point per unit time
44. Period - time taken by a particle to complete one oscillation
45. Intensity - rate of energy transfer per unit area
46. Transverse wave - a wave on which oscillations of particles are perpendicular to the direction of propagation of the wave
47. Longitudinal wave - a wave on which oscillations of particles are parallel to the direction of propagation of the wave
48. Diffraction - spreading of a wave into its geometrical shadow when it passes through a slit
49. Principle of superposition - when two or more waves meet at a point, the resultant displacement is equal to the sum of the individual displacement of each wave
50. Coherent sources - sources of wave with constant phase difference
51. Electric field - a region in space where a charge experiences an electric force
52. Electric field strength - force per unit positive charge
53. Charge - product of current and time
54. coulomb - ampere second
55. volt - joule / coulomb
56. ohm - volt / ampere
57. Potential difference - energy per unit charge converted from electrical energy to other forms of energy
58. e.m.f - energy per unit charge converted from other forms of energy to electrical energy
59. Resistance - ratio of p.d. to current
60. Kirchhoff's 1st Law - Algebraic sum of the currents at a junction is zero
61. Kirchhoff's 1st Law - sum of currents into a junction = sum of currents out of the junction
62. Kirchhoff's 2nd Law - In a closed loop of circuit, the algebraic sum of the potential difference is equal to the algebraic sum of the e.m.f
63. Isotopes - nuclei of a particular element with the same number of protons, but different number of neutrons