Speed and velocity sim
Speed is how fast; velocity is how fast in a stated direction.
Speed and velocity · covers the GCSE, IGCSE, O-Level topic
What the sim shows
Speed is how fast; velocity is how fast in a stated direction. The car goes round at a steady 4 m/s, so the speedometer never moves. But its direction turns all the time, so its velocity is always changing. In each second it changes by 1.98 m/s: the dashed arrow from the velocity one second ago to the velocity now. A change in velocity means the car is accelerating, even though its speed stays the same. One lap of the 8 m lane takes 12.6 s. The model is drawn at 1 m to 8 mm; the car goes round clockwise, as in Singapore.
- The car's velocity arrow
- Right: speedometer and velocity arrows
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 →
Need a version for your exact set-up? Have one made: US$49 a figure in an order of 5.
More physics sims
- Size ladder: atom to Earth simDrag a zoom slider along a powers-of-ten rail from 10⁻¹⁰ m to 10⁷ m and record the real objects that come into view, from a hydrogen atom to the Earth, with their sizes in prefixes and standard form.
- Leslie cube: emitters and absorbers of infrared simPour hot water into a Leslie cube, read a thermopile 10 cm from each face over three rounds as it cools, then time which waxed pin drops first beside a radiant heater.
- Refraction through a rectangular glass block simSet a ray box or pins, mark the ray, measure i and r with a protractor, and find n from the gradient of sin i against sin r.
- Black-body radiation: temperature and colour simTurn up the supply to a lamp and watch its filament go from giving out only infrared to dull red, orange, yellow and yellowish white while its emission curve's peak moves to shorter wavelengths and its total power climbs; then warm a black or shiny can in a lamp's light until it absorbs as fast as it gives out, and see the same balance set the Earth's temperature.
- Charge flow and current simClose the switch on a real series loop and watch the lamp light at once while every ammeter reads the same; drag a magnifier over any lead to see the electrons drift from − to + against the conventional current, time a run, work out Q = I × t yourself (✗ reasons for mA and ms) and check it against a coulomb counter.
- Combining resistors simDrag real resistors into the clips of a resistance board to wire them in series or in parallel, measure V and I with real digital meters, work out R = V ÷ I from your own readings and check it against the series and parallel formulas, and see that adding a parallel branch lowers the total while adding in series raises it.