Basics of A-Level of Physics Flashcards
Prefixes: What are all the prefixes?
Terra (T), Giga (G), Mega (M), Kilo (k), Centi (c), Milli (m), Micro (u with one long side), Nano (n), Pico (p)
Power of Ten for Terra
X10^12
Power of ten for Giga
X10^9
Power of ten for Mega
X10^6
Power of ten for kilo
X10^3
Power of ten for Centi
X10^-3
Power of ten for Milli
X10^-3
Power of ten for Micro
X10^-6
Power of ten for Nano
X10^-9
Power of ten for Pico
X10^-12
When you have really large or small numbers what should you convert them to?
Always to the power of ten I.e. 65x10^-3, 3x10^-2
What are the BASE S.I units
Mass (kg), length (m), time (s), current in ampere (A), Temperature (k), Amount of substance (mol), luminous intensity in candela (c.d)
What are the derived units?
Voltage (v), Power (W), Energy (J), Velocity (ms-1), acceleration (ms-2), Pressure (Pa), Force (N), Density (Kgm-3), Temperature (°C)
What is the base unit of 1N?
1kgms^-2
What is the base unit of 1J?
1kgm^2s^-2
What is the base unit of 1Pa
1kgm^-1s^-2
What are random errors?
These cause unpredictable fluctuations in an instrument’s readings as a result of uncontrollable factors, such as environmental conditions. This affect the precision of the measurements taken, causing a wider spread of results the mean value.
How do use reduce the amount of random errors?
Repeat measurements several times and calculate an average from them.
Systematic errors
Systematic errors arise from the use of faulty instruments used or from flaws in the experimental method. This type of error is repeated consistently every time the instrument is used or the method is followed, which affects the accuracy of all readings obtained.
How do you reduce systematic errors?
Instruments should be recalibrated, or different instruments should be used. Corrections or adjustments should be made to the technique.
What are zero errors?
This is a type of systematic error which occurs when an instrument gives a reading when the true reading is zero. This introduces a fixed error into readings which must be accounted for when the results are recorded.
What is precision?
Precise measurements are ones in which there is very little spread about the mean value.
What is accuracy?
A measurement is considered accurate if it is close to the true value.
What is repeatability?
A measurement is repeatable if the original experimenter repeats the investigation using the same method and equipment and obtains the same results.
What is reproducibility?
A measurement is reproducible if the investigation is repeated by another person, or by using different equipment or techniques, and the same results are obtained.
What is resolution?
The smallest change in the quantity being measured of a measuring instrument that gives a perceptible change in the reading.
Percentage uncertainty equation
Percentage uncertainty = Uncertainty/measured value x 100
