Free fall, flash by flash sim
The switch cuts the electromagnet's current and the ball falls from rest.
Free fall, flash by flash · covers the GCSE, IGCSE, O-Level topic
What the sim shows
The switch cuts the electromagnet's current and the ball falls from rest. The stroboscope flashes 10 or 20 times a second, so the photograph shows where the ball was at equal time intervals T. The images get further apart: the ball speeds up. Each gap is longer than the one before by the same amount, g T², so g = (change in gap) ÷ T². With a flash every 0.1 s the gaps are 5, 15 and 25 cm, each 10 cm more than the last: g = 0.10 m ÷ (0.1 s)² = 10 m/s². Taking g = 10 m/s² as in the lesson, with air resistance ignored. Shown at 0.1× speed.
- The ball at each flash
- Right: the photograph, gaps in cm
Use it in your lessons
- Try it here: anyone can unlock 2 figures free, and a free account unlocks up to 5. Runs on a laptop, a Chromebook or a phone; nothing to install.
- Present it and share student links with the teacher plan, from US$5 a month, billed yearly.
- Put it on your own website or LMS for US$9, paid once, or every sim from US$29 a month.
Free guide: 12 practicals as sims, and how to run one in a lesson →
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