Physics Definitions Table
Required Vocabulary – IB 12 Higher Level
Physics and Physical Measurement
1. Fundamental Units – seven basic units of the SI measurement system: kilogram, second, mole, meter, ampere, Kelvin, candela.
2. Derived Units – units that are combinations of fundamental units. These combinations may or may not have a separate name. (eg. 1 kg m/s2 = 1 N)
3. Accuracy - An indication of how close a measurement is to the accepted value (a measure of correctness).
4. Precision - An indication of the agreement among a number of measurements made in the same way (a measure of exactness).
5. Random Uncertainty - An uncertainty produced by unknown and unpredictable variations in the experimental situation, such as temperature fluctuations and estimations when reading instruments. (Affects the precision of results - Can be reduced by taking repeated trials but not eliminated – shows up as error bars on a graph)
6. Systematic Error - An error associated with a particular instrument or experimental technique that causes the measured value to be off by the same amount each time. (Affects the accuracy of results - Can be eliminated by fixing source of error – shows up as non-zero y-intercept on a graph)
7. Vector – a quantity with both a magnitude and a direction
8. Scalar – a quantity with magnitude only
Mechanics
9. *Displacement (s) - distance traveled from a fixed point in a particular direction
10. *Velocity (u,v) - rate of change of displacement
11. *Speed (u,v) - rate of change of distance
12. *Acceleration (a) - rate of change of velocity
13. *Newton’s First Law of Motion – An object at rest remains at rest and an object in motion remains in motion at a constant speed in a straight line unless acted on by an unbalanced force.
14. *Newton’s Second Law of Motion – An unbalanced force will cause an object to accelerate in the direction of the net force. The acceleration of the object is proportional to the net force and
Physics and Physical Measurement
1. Fundamental Units – seven basic units of the SI measurement system: kilogram, second, mole, meter, ampere, Kelvin, candela.
2. Derived Units – units that are combinations of fundamental units. These combinations may or may not have a separate name. (eg. 1 kg m/s2 = 1 N)
3. Accuracy - An indication of how close a measurement is to the accepted value (a measure of correctness).
4. Precision - An indication of the agreement among a number of measurements made in the same way (a measure of exactness).
5. Random Uncertainty - An uncertainty produced by unknown and unpredictable variations in the experimental situation, such as temperature fluctuations and estimations when reading instruments. (Affects the precision of results - Can be reduced by taking repeated trials but not eliminated – shows up as error bars on a graph)
6. Systematic Error - An error associated with a particular instrument or experimental technique that causes the measured value to be off by the same amount each time. (Affects the accuracy of results - Can be eliminated by fixing source of error – shows up as non-zero y-intercept on a graph)
7. Vector – a quantity with both a magnitude and a direction
8. Scalar – a quantity with magnitude only
Mechanics
9. *Displacement (s) - distance traveled from a fixed point in a particular direction
10. *Velocity (u,v) - rate of change of displacement
11. *Speed (u,v) - rate of change of distance
12. *Acceleration (a) - rate of change of velocity
13. *Newton’s First Law of Motion – An object at rest remains at rest and an object in motion remains in motion at a constant speed in a straight line unless acted on by an unbalanced force.
14. *Newton’s Second Law of Motion – An unbalanced force will cause an object to accelerate in the direction of the net force. The acceleration of the object is proportional to the net force and