Tools and Inquiry — IB Physics skills
I.1.1 Exploring in Physics — IB Physics HL Revision Notes & Topical Questions
5 min read 9 parts Lesson 15 of 22 1 quiz
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Lesson summary
I.1.1 Exploring in Physics — IB PHYSICS SL notes: Develop a focused research question and a testable, justified hypothesis from background research.Exploring is the creative start of an investigation — using curiosity and physics knowledge.It aims to produce a focused research qu…
- It needs independent thinking and a variety of sources
- Good investigations often start from a simple question about a standard experiment
- Insight is shown by framing a comparative question
- Good starting points
- Check feasibility
- Research gives scientific context
Part 1 of 7Purpose of exploring
Purpose of exploring
Exploring is the creative start of an investigation
- Exploring is the creative start of an investigation using curiosity and physics knowledge.
It aims to produce a focused research question and a testable hypothesis.
It needs independent thinking and a variety of sources
- It needs independent thinking and a variety of sources to understand the scientific context and justify a prediction.
Part 2 of 7Independent thinking and insight
Independent thinking and insight
Good investigations often start from a simple question about a standard experiment
- e.g. measuring g.
Insight is shown by framing a comparative question
- Insight is shown by framing a comparative question e.g. does the mass of a pendulum bob affect its period?
- This tests the assumptions inside a physical model.
Investigate one independent variable and one dependent variable in depth.
- Questions with several factors at once (length and mass together) are too broad.
Good starting points
- Good starting points a surprising class result, a different aspect of a standard experiment, or a real-world product such as sports balls.
Check feasibility
- Check feasibility equipment, sensors and time must allow the investigation.
Part 3 of 7Consulting sources
1
Background research is needed before a high-quality question.
2
It helps to understand the underlying physical principle.
- It finds established values for comparison.
- It identifies a suitable method for collecting data.
3
Sources include notes, textbooks, the IB data booklet and reliable simulators such as PhET.
- Databases such as NIST or the CRC Handbook give accepted values, e.g. resistivity or specific heat capacity.
4Research gives scientific context
- Research gives scientific context it shows that you understand the physics behind the question.
Part 4 of 7Research question
1
A research question must be focused and specific.
2
It must state the link between the independent and dependent variable.
3Typical form
- Typical form what is the relationship between x and y?
- Too generalhow does gravity affect objects?
- Focusedwhat is the relationship between the length of a simple pendulum and its period of oscillation?
4Refine it if research shows the first idea is impractical
- Refine it if research shows the first idea is impractical this is part of the scientific process.
Part 5 of 7Hypothesis
Hypothesis
A hypothesis is a clear, testable statement that predicts an outcome with a scientific justification — it is not a guess.
Structure
- Structure if, then (predicted effect), because (physics reason).
- (change to the independent variable)
The because part rests on established principles
- Newton's laws, conservation of energy or a formula.
- "The period will increase with length" is only a prediction.
- Adding that T = 2π√(L/g) makes T proportional to √L turns it into a hypothesis.
Conservation of energy can justify a calorimetry method
- Conservation of energy can justify a calorimetry method thermal energy lost by the metal equals energy gained by the water.
Part 6 of 7Predictions from equations
Use an equation to see which variables matter and which do not.
- The pendulum period equation contains L and g but not mass — so period should be independent of mass.
- Resistivity ρ = RA/L predicts resistance directly proportional to length and inversely proportional to cross-sectional area.
- Q = mcΔT links energy transferred to temperature change in specific heat capacity.
State the assumptions
- State the assumptions constant temperature and cross-sectional area for the wire, small angle for the pendulum.
Part 7 of 7More from the specification
More from the specification
Experimental Design and Variable Control
- A rigorous physics methodology requires identifying the independent, dependent,
- and controlled variables to ensure an experiment provides valid, repeatable measurements.
Identifying and Correcting Systematic Errors
- Systematic errors consistently shift measurements away from true values in one direction;
- instruments like micrometers and calipers must be checked for zero error before data collection.
Random Errors and Uncertainty Analysis
- Random errors cause scatter around the mean value;
- taking repeated measurements and calculating an arithmetic average reduces random uncertainty and improves experimental precision.
Controlling Thermal Effects in Electrical Circuits
- When measuring electrical resistance or current-voltage characteristics, power supplies should only be switched on briefly to prevent temperature increases from altering conductor resistance.
Experimental Design and Variable Control
- A rigorous physics methodology requires identifying the independent, dependent,
- and controlled variables to ensure an experiment provides valid, repeatable measurements.
Identifying and Correcting Systematic Errors
- Systematic errors consistently shift measurements away from true values in one direction;
- instruments like micrometers and calipers must be checked for zero error before data collection.
Random Errors and Uncertainty Analysis
- Random errors cause scatter around the mean value;
- taking repeated measurements and calculating an arithmetic average reduces random uncertainty and improves experimental precision.
Controlling Thermal Effects in Electrical Circuits
- When measuring electrical resistance or current-voltage characteristics, power supplies should only be switched on briefly to prevent temperature increases from altering conductor resistance.
Methodology
- Step-by-step procedure that another person can replicate.
Control variable
- A quantity kept the same to make the test fair
Systematic error
- An error that shifts all readings the same way, such as a balance not zeroed.
Small-angle approximation
- Sin θ ≈ tan θ ≈ θ for small θ in radians.
Background radiation
- Radiation that is always present in the environment.
Key terms
| Term | Meaning |
|---|---|
| Research question | Focused question linking an independent and a dependent variable. |
| Hypothesis | Testable prediction with a scientific justification. |
| Independent variable | The variable deliberately changed. |
| Dependent variable | The variable measured as the outcome. |
| Feasibility | Whether the investigation can be carried out with available equipment and time. |
| Accepted value | Reliable literature value used for comparison. |
Avoid these mistakes
1
Choosing a question that is too broad — it must link one independent and one dependent variable.
2
Writing a hypothesis as a guess with no scientific reason.
3
Investigating several independent variables at once.
4
Not checking feasibility of equipment and time.
5
Omitting accepted values or theory that the results will be compared with.
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