Module 2 Chapter 1 Physical Quantities, Units and Measurements Flashcards
1
Q
Unit for Acceleration
A
m s-2
metres per second squared
2
Q
Unit for Density
A
kg m-3
kilograms per cubic metre
3
Q
Unit for Electrical Charge
A
C
coulomb
4
Q
Unit for Energy
A
J
joule
5
Q
Unit for Force
A
N
newton
6
Q
Unit for Momentum
A
kg m s-1
kilogram metres per second
7
Q
Unit for Potential Difference
A
V
volt
8
Q
Unit for Power
A
W
watt
9
Q
Unit for Pressure
A
Pa
pascal
10
Q
Unit for Velocity
A
m s-1
metres per second
11
Q
Prefix: pico
A
p
10^-12
12
Q
Prefix: nano
A
n
10^-9
13
Q
Prefix: micro
A
µ
10^-6
14
Q
Prefix: milli
A
m
10^-3
15
Q
Prefix: centi
A
c
10^-2
16
Q
Prefix: kilo
A
k
10^3
17
Q
Prefix: mega
A
M
10^6
18
Q
Prefix: giga
A
G
10^9
19
Q
Prefix: tera
A
T
10^12
20
Q
SI Unit for Mass
A
kg
Kilogram
21
Q
SI Unit for Length
A
m
Metre
22
Q
SI Unit for Time
A
s
Second
23
Q
SI Unit for Temperature
A
K
Kelvin
24
Q
SI Unit for Electrical Current
A
A
Ampere
25
SI Unit for Amount of Substance
mol
| Mole
26
SI Unit for Luminous Intensity
cd
| Candela
27
Examples of Random Errors
- Variable heating in circuits causing variations in the current being measured
- An unexpected large extension of a metal wire due to a fault in its structure
28
Examples of Systematic Errors
- Using a ruler with a fault in the measurements printed on it
- A parallax error caused by reading a scale at the wrong angle
29
What do random errors reduce?
Precision
30
What do systematic errors reduce?
Accuracy
31
Percentage Uncertainty Formula
(uncertainty/measured value) * 100
32
How can one measure uncertainty?
By using one of two methods:
- Calculating a % difference between your 'best' and 'worst' lines of best fit
- Combining your uncertainties for each of your measurements (either summing or multiplying them depending on how you use the values)
33
For y = ab, how would you find the uncertainty of y, given the uncertainties of a and b?
% uncertainty in y = % uncertainty in a + % uncertainty in b
34
For y = a/b, how would you find the uncertainty of y, given the uncertainties of a and b?
% uncertainty in y = % uncertainty in a + % uncertainty in b
35
For y = a^n, how would you find the uncertainty of y, given the uncertainty of a?
% uncertainty in y = (% uncertainty in a) * n
36
For y = a ± b, how would you find the uncertainty of y, given the uncertainties of a and b?
absolute uncertainty of y = absolute uncertainty of a + absolute uncertainty of b
