CHP 1 measurements Flashcards
What are the 5 physical quantities?
1) Length, metre, m
2) Temperature, kelvins, K
3) Mass, kilogram, kg
4) Electric current, ampere, A
5) Time, seconds, s
What are the 8 prefixes?
1) Giga, G, 10^9
2) Mega, M, 10^6
3) Kilo, K, 10^3
4) Deci, d, 10^-1
5) Centi, c, 10^-2
6) Milli, m, 10^-3
7) Micro, µ, 10^-6
8) Nano, n, 10^-9
How to change base units to unites with prefixes?
Base unit ÷ unit with prefix
How to change unit with prefixes to base units?
Unit with prefix x unit with prefix
What is a scalar quantity?
A quantity that has magnitude only (units)
What is a vector quantity?
A quantity that has both magnitude and direction
What is a systematic error? Give 2 examples
Instruments are faulty and physical constraints of human, eg. zero error, human reaction time
What is random error? Give an example
Carelessness of observer, eg. parallax error
What is the accuracy of a vernier caliper?
0.01cm (2dp)
How to calculate negative (zero error) error on vernier caliper?
-(0.10-measurement) cm
What is the accuracy of a micrometer screw gauge?
0.01mm (2dp)
How to calculate negative (zero error) error on micrometre screw gauge?
-(0.50-measurement) mm
What is a period?
The time taken for one complete oscillation of the pendulum
Why take the time for 20 complete oscillations than 1?
To minimise errors made by human reaction time so as to get a more accurate measurement
Why repeat the process of taking 20 complete oscillations 3 times and then find the average period?
To improve the accuracy of the experiment
