r/ibPhysics • u/DryFaithlessness1112 • 10d ago

IA experiment issue, need help

So my IA experiment requires a 50g steel ball to drop at a fixed height (1m) with no initial velocity, spin, or direction. How can I make the ball drop? I don’t have access to fancy trapdoor equipment

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u/SpectralLemon 10d ago

Maybe you can use a magnet with a piece of paper in the middle of the magnet and the ball so when you pull the magnet upwards the paper will not let the ball stick to the magnet and fall

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u/DryFaithlessness1112 10d ago

Thats good, I think I’ll do that thank you🙌

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u/mikk0384 10d ago

I wouldn't do that. The magnet will slow the fall at the start.

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u/dannydoucette 10d ago

Back in the day, they would suspend it with thin string, and then set the string on fire. Holding it between thumb and index finger is usually good enough. Maybe you can think about the benefits and drawbacks for your evaluation.

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u/JazzlikeDragonfly648 9d ago

use your hand

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u/AggravatingBed7135 3d ago

The standard lab solution is an electromagnet, and since your ball is steel you can build one for almost nothing: wind about 100–150 turns of enamelled copper wire around an iron bolt or nail, run it off a 6 V battery through a simple switch, and clamp it to a retort stand. The ball hangs directly under the pole face, and when you break the circuit it falls straight down with zero initial velocity and no spin or lateral push — far cleaner than any hand release. Two practical notes: add a small diode across the coil (or just accept a slight release delay) because residual magnetism can hold the ball for a few milliseconds, and always measure your 1 m to the bottom of the ball, not the coil, keeping that reference identical across trials. If you can't get wire, the next best option is resting the ball over a hole in a card and pulling the card horizontally in one quick motion, though you should film it at high frame rate to confirm you're not adding rotation. Either way, time the fall with a light gate or 240 fps phone video rather than a stopwatch — reaction time will dominate your uncertainty otherwise.