Angular kinematics
API · /centripetal-api
Circular Motion API
healthy
3,462 Subscribers
Uniform circular-motion physics as an API, computed locally and deterministically. The centripetal-force endpoint computes the centripetal acceleration a = v²/r = ω²·r — always pointing toward the centre — and the centripetal force F = m·a that holds a body on its circular path, from the mass, the radius and either the linear or the angular velocity, and reports the equivalent g-force. The angular endpoint converts between every way of describing rotation — angular velocity (rad/s), revolutions per minute, frequency, period and, given a radius, the linear (tangential) velocity — using ω = 2π·f = 2π/T = v/r. The centrifuge endpoint computes the relative centrifugal force (RCF, in g) of a centrifuge rotor from its speed in rpm and radius, RCF = ω²·r / g, or inverts it to give the rpm needed to reach a target RCF. Masses are in kg, radii in m (mm for the centrifuge), velocities in m/s, angular velocities in rad/s and forces in N. Everything is computed locally and deterministically, so it is instant and private. Ideal for physics-education, mechanical, automotive, lab-centrifuge and amusement-ride app developers, rotational-motion and g-force tools, and STEM teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is uniform circular motion; for gravitational orbits use a gravitation API, for a vehicle on a banked curve a banked-curve API and for pendulum oscillation a pendulum API.
api.oanor.com/centripetal-api
API health
healthy- Uptime
- 100.00%
- Server probes · 24h
- Avg latency
- 72 ms
- Server probes · 24h
- Subscribers
- 3,462
- active
- Total calls
- 76
- last 7 days
Pricing
Pick a tier — billed monthly, cancel anytime.
Free
Free
- 4,000 calls / month
- 2 requests / second
- Hard cap (429 above quota, no overage)
- 4,000 calls/month
- 2 req/sec
- Centripetal force + angular + centrifuge
- No credit card
Starter
€4.00 /month
- 36,000 calls / month
- 6 requests / second
- Hard cap (429 above quota, no overage)
- 36,000 calls/month
- 6 req/sec
- rpm/rad/s/Hz conversions, g-force
- Email support
Pro
€13.00 /month
- 210,000 calls / month
- 15 requests / second
- Hard cap (429 above quota, no overage)
- 210,000 calls/month
- 15 req/sec
- Mechanical & centrifuge pipelines
- Priority support
Mega
€42.00 /month
- 1,250,000 calls / month
- 40 requests / second
- Hard cap (429 above quota, no overage)
- 1,250,000 calls/month
- 40 req/sec
- Platform scale
- Dedicated SLA
Built by
Related APIs
Other APIs with overlapping tags.
Banked Curve API
Banked-curve and circular-motion dynamics as an API, computed locally and deterministically. The speed endpoint takes the radius of a curve and its banking (bank) angle and returns the frictionless ideal (design) speed at which the banking alone supplies the centripetal force, v = √(r·g·tanθ); give a coefficient of friction as well and it also returns the maximum safe speed before the vehicle slides outward up the bank, v = √(r·g·(tanθ+μ)/(1−μ·tanθ)), and the minimum speed before it slides inward down the bank — every speed in metres per second, km/h, mph and knots, plus the centripetal acceleration. The bank-angle endpoint inverts this: from a design speed and radius it returns the ideal banking angle θ = atan(v²/(r·g)) and the equivalent superelevation as a ratio and a percentage, the cant a road or railway needs so no side friction is used at that speed. The flat-curve endpoint handles an unbanked curve from the coefficient of friction: the maximum cornering speed v = √(μ·r·g) for a given radius and the minimum radius v²/(μ·g) for a given speed. Gravity defaults to standard 9.80665 m/s² and can be overridden. Everything is computed locally and deterministically, so it is instant and private. Ideal for road and racetrack design tools, vehicle-dynamics and driving-simulator apps, civil and transportation engineering, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is curve banking and cornering dynamics; for projectile and SUVAT kinematics use a physics API.
api.oanor.com/bankedcurve-api
Isotopes API
Atomic isotope reference data as an API, built on the NIST Atomic Weights and Isotopic Compositions. For every known nuclide: its element (atomic number Z and symbol), mass number, relative atomic mass, natural isotopic composition (abundance) and the element's standard atomic weight. Look an isotope up by label (C-12, U-238) or by symbol + mass, list every isotope of an element, rank isotopes by mass or natural abundance, or search. A precise physics and chemistry reference for science, education, lab and engineering apps. Distinct from element-level data.
api.oanor.com/isotopes-api
Hot Air Balloon Lift API
Hot-air-balloon lift maths as an API, computed locally and deterministically — the thermal-lift, envelope-temperature and air-density numbers a balloon pilot, designer or physics teacher works a flight out with. The lift endpoint gives the buoyant lift from heating the air: gross lift = envelope volume × (outside air density − inside air density), the densities from the ideal-gas law — a 2,500 m³ envelope at 100 °C on a 15 °C day lifts about 698 kg gross, from which you subtract the envelope, basket, burner and fuel for the payload, and the hotter the air and colder the day the more it lifts. The required-temp endpoint inverts it: to carry a target lift the inside air must reach a particular density and so a particular temperature, with a check that it stays under the ~120 °C that nylon envelopes can take — the everyday pre-flight question of whether the balloon can lift today's crew and fuel. The air-density endpoint gives the moist-air density ρ = (P − 0.378·Pv) ÷ (R·T), and explains the counter-intuitive fact that humid air is LESS dense than dry air, slightly cutting the lift. Everything is computed locally and deterministically, so it is instant and private. Ideal for ballooning and aviation tools, STEM and physics-education apps, and buoyancy calculators. Pure local computation — no key, no third-party service, instant. Idealised dry-lift model. 3 compute endpoints. For Archimedes flotation in water use a buoyancy API; for party-balloon helium lift a balloon API.
api.oanor.com/hotairballoon-api
Vacuum Technology API
Vacuum-technology maths as an API, computed locally and deterministically — the pump-down, boiling and pressure numbers a lab tech, process engineer or vacuum hobbyist works to. The pumpdown endpoint gives the ideal time to evacuate a chamber, t = (volume ÷ pump speed) × ln(start ÷ target pressure) — a 10-litre chamber on a 5 L/s pump drops from 1000 to 1 mbar in about 14 seconds in theory, though outgassing and falling pump speed stretch the real low-pressure stage. The boiling-point endpoint gives the temperature water boils at under reduced pressure from the Antoine equation: about 100 °C at sea level, but only ~52 °C at 100 mbar and ~46 °C at 100 mbar — the physics behind vacuum degassing, freeze-drying and high-altitude cooking. The level endpoint converts a pressure across the common vacuum units (mbar, Torr/mmHg, Pa, kPa, inHg, atm, psi), reports the percent vacuum relative to atmosphere, and names the regime — rough, medium, high or ultra-high vacuum — so you know which pump and gauge the job needs. Everything is computed locally and deterministically, so it is instant and private. Ideal for vacuum-lab and process apps, pump-sizing and degassing tools, semiconductor and coating calculators, and physics teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. Ideal estimates — real systems are slowed by outgassing and leaks.
api.oanor.com/vacuum-api
Frequently asked questions
Quick answers about pricing, quotas, and integration.
How do I get an API key for Circular Motion API?
Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Circular Motion API with the x-oanor-key header. No credit card needed for the free tier.
What's the rate limit for Circular Motion API?
Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.
How much does Circular Motion API cost?
Circular Motion API has a free tier with 100 calls / month. Paid plans start at €4.00 / month with higher quotas and faster rate limits.
Can I cancel my subscription anytime?
Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.
Is Circular Motion API GDPR-compliant?
All requests to Circular Motion API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.
Pick an endpoint from the list on the left to see its details and try it.
Code snippets
Sign up to get an API key, then call any path under your slug.
curl https://api.oanor.com/centripetal-api/SOME_PATH \
-H "x-oanor-key: oanor_test_..."const res = await fetch("https://api.oanor.com/centripetal-api/SOME_PATH", {
headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();$ch = curl_init("https://api.oanor.com/centripetal-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);import requests
r = requests.get(
"https://api.oanor.com/centripetal-api/SOME_PATH",
headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())Ratings
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