Scientific Skills Flashcards
Giga
Symbol: G
Exponent: 10^9
Mega
Symbol: M
Exponent: 10^6
Kilo
Symbol: k
Exponent: 10^3
Pico
Symbol: p
Exponent: 10^-12
Nano
Symbol: n
Exponent: 10^-9
Micro
Symbol: µ
Exponent: 10^-6
Milli
Symbol: m
Exponent: 10^-3
Centi
Symbol: c
Exponent: 10^-2
Deci
Symbol: d
Exponent: 10^-1
km.h^-1 to m.s^-1
1000m/3600s
m.s^-1 to km.h^-1
3600s/1000m
In Physical Science we conduct experiments in order to
Prove our hypothesis
Types of relationships:
- Directly proportional
- Inversely proportional
Simple Direct Proportion
- y = mx
- m is gradient & constant
- 2 variables only directly proportional when graph is single line through origin
- Plotted to give straight line: y vs x
- Mathematical formula: y/x = m
Simple Inverse Proportion
- y = m/x
- The graph has a hyperbola
- If 1/x then graph will be directly proportional (straight line through origin)
- Plotted to give straight line: y vs 1/x
- Mathematical formula: yx = m
Skills needed to analyse Practical Investigations
- Conducting an investigation
- Choosing variables
- Conducting an investigation (method)
- Making measurements
- Making observations
- Recording results
- Representing results
Conducting an investigation
- Ask an investigative question (include variables)
- Investigation questions must be testable
Hypothesis
- Refer to independent and dependent variables
- Phrased as a statement, not a question (starts with “if…then…”)
- Must be a testable generalisation/relationship and not a prediction of an observation
To conduct the investigation:
- Adjust 1 factor
- Keep all other conditions the same
- Observe the effects of the changes made
In a fair test
A change in the independent variable alone causes a change in the dependent variable and all other variables remain unchanged
Method must be:
- Detailed and accurate, so if repeated the same results are obtained
- Bulleted/numbered
- Described in 3rd person past tense
Making measurements
- Avoid error of parallax: eye must be in line with the measuring line
- Read off instrument and always estimate 1 further decimal place
Results are usually recorded in a
Table
Graphs are used to represent results:
- To establish relationship between variables
- Makes it easy to see your findings at a glance
Line graphs
Continuous independent variable (like time) and a constant change in dependent variable between readings
Best fit line:
- Drawn when a graph is showing a trend/constant relationship
- Averages/removes error readings and should have an equal number of points above and below the line
Gradient formula
M = y2-y1/x2-x1
