Tools and Inquiry — IB Physics skills

T.2.1 Applying Technology to Collect Data in Physics — IB Physics HL Revision Notes & Topical Questions

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Lesson summary

T.2.1 Applying Technology to Collect Data in Physics — IB PHYSICS SL notes: Use sensors, data loggers, databases, simulations and video analysis to collect data in physics.Technology helps spot patterns and make predictions from large data sets.Large data sets come from experimen…

It does not remove uncertainty
Light gates
Motion sensors
Force sensors
Temperature probes
Pressure sensors

Part 1 of 8Why use technology

Why use technology

Technology helps spot patterns and make predictions from large data sets.

Large data sets come from experiments, sensors, existing databases, or models and simulations.

It does not remove uncertainty

It does not remove uncertainty it only changes where the uncertainty lies.
State the resolution of a digital tool and test it against a known measurement.

Part 2 of 8Sensors

Sensors

Sensors devices that detect changes in physical quantities and convert them into electrical signals.

Light gates

Light gates time intervals very precisely, e.g. two gates give the speed of a trolley.
- (v = card width / t)

Motion sensors

Motion sensors detect position or velocity of moving objects.

Force sensors

Force sensors measure forces over short time intervals.

Temperature probes

Temperature probes monitor heating or cooling.

Pressure sensors

Pressure sensors measure the pressure of gases or liquids.

Digital ammeters, voltmeters and multimeters

Digital ammeters, voltmeters and multimeters record current, potential difference and resistance.

Part 3 of 8Data loggers

1A data logger converts the sensor signal to a digital signal

A data logger converts the sensor signal to a digital signal or sends it straight to a computer.

Results can be displayed in real time on a screen.

Data can be stored, processed into averages and graphs, and analysed for gradients and uncertainties.

Advantages.

More precise results than manual timing or measurement.
Less human error, such as reaction time and subjectivity.
Data over very short or very long periods, e.g. hourly temperatures over several days.
Large amounts of data, stored and analysed digitally.
Greater safety, e.g. measuring boiling water.

Part 4 of 8Sampling rate and resolution

Sampling rate and resolution

Sampling rate

Sampling rate the number of readings per second — it must match how fast the quantity changes.

Too low a rate misses detail or distorts the signal (aliasing).
Too high a rate wastes memory and records noise.

Choose the rate from a short preliminary trial

Choose the rate from a short preliminary trial a cooling beaker needs a reading every 30 s, a 20 ms collision needs at least 1 kHz.

Resolution depends on converter bits

Resolution depends on converter bits an 8-bit logger has 256 levels.

Part 5 of 8Databases

A database

A database a structured collection of data that can be searched, sorted, filtered and analysed.

Data can be text, images, video or audio.

Examples

Examples material properties, astronomical data on stars and exoplanets, and particle physics data from CERN.
- (density, resistivity, specific heat capacity)

Secondary data from databases must be referenced.

Part 6 of 8Models and simulations

Models and simulations

A model

A model a simplified version of reality — used to represent and explain phenomena and predict responses to change.

Simulations explore scenarios that are unsafe or not feasible in a laboratory.

You can alter variables and see the effect

You can alter variables and see the effect e.g. a gas simulation predicts changes with temperature, pressure and volume.

Accuracy depends on the quality of the model and assumptions

Accuracy depends on the quality of the model and assumptions simulation output is not a real measurement.

PhET provides online simulations of many physics scenarios

PhET provides online simulations of many physics scenarios state the parameters used.

Part 7 of 8Video and image analysis of motion

Video and image analysis of motion

Film the object in front of a measurement grid or ruler with a camera or smartphone.

Play frame by frame or use software that tracks positions

Play frame by frame or use software that tracks positions velocity and acceleration follow from position and time.

Useful for fast or complex motion

Useful for fast or complex motion free fall, projectiles, collisions and oscillations.

Two things must be known.

Frames per second, to find the time.
The scale of the frame, usually by putting a ruler in the shot.

Place the camera perpendicular to the motion and keep it still

Place the camera perpendicular to the motion and keep it still to avoid perspective error.

Part 8 of 8More from the specification

Automated data acquisition in physics
- digital interface sensors log kinematic and thermodynamic parameters continuously across the entire experimental physical system.

Key terms

Term	Meaning
Sensor	Device converting a physical quantity into an electrical signal.
Data logger	Device recording sensor readings automatically.
Sampling rate	Number of readings taken per second.
Light gate	Sensor timing how long a beam is blocked by a passing object.
Database	Structured collection of data that can be searched and analysed.
Simulation	Computer model imitating a physical system.
Aliasing	False apparent frequency caused by sampling too slowly.

Avoid these mistakes

Using a sampling rate too low for the signal — rapid changes are missed or distorted.

Treating a simulation as a real measurement with measurement uncertainty.

Trusting the number of digits displayed by a sensor as its accuracy.

Filming at an angle to the motion — distances in the video are not true distances.

Forgetting to zero or calibrate a sensor before the experiment.

Last updated: 18 October 2026