StarlyLab for teachers Ready-to-use lab activities with the students' smartphones

• Level: Upper secondary
• Time: 50–60 min
• Instruments: Pendulum, stopwatch, notebook graph

Goal: Find the acceleration of gravity from the period of a pendulum and estimate the error.

What students do:

1. Formulate a hypothesis: does the mass change the period?
2. Measure the period for 4 different lengths (10 oscillations each).
3. Plot T² against L and find g from the slope (4π²/g).

Discussion question: Why does the period not depend on the mass?

Read the guide

• Level: Upper secondary
• Time: 50 min
• Instruments: Light meter

Goal: Show that illuminance decreases with the square of the distance from a small light source.

What students do:

1. In a darkened room, place a small lamp or another phone's flashlight at the same height as the light sensor.
2. Measure the illuminance at 20, 30, 40, 60 and 80 cm.
3. Plot illuminance against 1/d²: the points should lie on a straight line.

Discussion question: Why do the points close to the lamp deviate if the lamp is large?

• Level: Upper secondary
• Time: 50–60 min
• Instruments: Spectrum analyzer (FFT)

Goal: Measure the speed of sound from the resonance of an air column closed at one end.

What students do:

1. Use a tall cylindrical bottle or tube, partly filled with water, and measure the length L of the air column and its diameter d.
2. Blow across the opening and read the main frequency f on the spectrum analyzer.
3. Compute v = 4 f (L + 0.3 d) and repeat with different water levels.

Discussion question: Why do we add 0.3 d to the length of the air column?

• Level: Upper secondary
• Time: 40 min
• Instruments: Barometer and altimeter (phones with a barometer)

Goal: Measure the density of air from the pressure difference between floors.

What students do:

1. Record the pressure on the ground floor and on the top floor of the school, keeping the phone still for a few seconds.
2. Measure the height difference h (count the steps and measure one).
3. Compute ρ = Δp / (g h) and compare it with about 1.2 kg/m³.

Discussion question: How much does the pressure change for each floor, and why do airplanes need pressurized cabins?

• Level: Upper secondary
• Time: 50 min
• Instruments: Earthquakes of the week, notebook table

Goal: Discover the Gutenberg-Richter law with real seismic data.

What students do:

1. Open this week's earthquakes in StarlyLab and write the magnitudes in the notebook table.
2. For each magnitude M, count how many earthquakes have magnitude ≥ M.
3. Plot log₁₀(N) against M and find the slope b, which is usually close to 1.

Discussion question: What does a b-value close to 1 tell us about how common small and large earthquakes are?

• Level: Upper secondary
• Time: 40 min
• Instruments: Reaction time test

Goal: Collect repeated measurements and learn mean, spread and comparison between groups.

What students do:

1. Each student does 10 trials with the dominant hand and 10 with the other hand.
2. Compute the mean and the standard deviation for each series.
3. Compare the class results: is the difference between hands larger than the spread?

Discussion question: How many trials do you need before you trust a difference?

• Level: Upper secondary (chemistry)
• Time: 50–60 min
• Instruments: Colorimeter with absorbance

Goal: Show that absorbance is proportional to concentration.

What students do:

1. Prepare 5 dilutions of a food coloring in identical clear containers.
2. Measure the absorbance of each one against a container of clean water.
3. Plot absorbance against concentration and use the line to find the concentration of an unknown sample.

Discussion question: Why should all containers have the same thickness?