{"success":true,"version":"v1","request":{"tool":"list_calculators","category":"physics"},"result":{"entity_type":"calculator_list","status":"completed","count":20,"calculators":[{"calculator_id":"speed-distance-time","entity_type":"calculator","name":"Speed, Distance & Time Calculator","category":"physics","tool_name":"solve_speed_distance_time","description":"Solves the uniform-motion relation speed = distance / time for whichever of the three quantities is omitted, and reports the speed in m/s, km/h and mph and the time as h:mm:ss.","use_when":"You know any two of distance, elapsed time and average speed for travel at constant (average) speed and need the third.","do_not_use_when":"Speed changes during the motion (use acceleration or free-fall), or you want a running pace per km or mile (use 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(use force), the motion is vertical under gravity alone (use free-fall), or you only need speed from distance and time (use speed-distance-time).","required_inputs":["final_velocity_m_s","time_s"],"optional_inputs":["initial_velocity_m_s"],"urls":{"html":"https://tttkmbb.com/physics/acceleration","markdown":"https://tttkmbb.com/physics/acceleration.md","schema":"https://tttkmbb.com/api/v1/calculators/acceleration","api":"https://tttkmbb.com/api/v1/calculate/acceleration"}},{"calculator_id":"newtons-second-law","entity_type":"calculator","name":"Force Calculator","category":"physics","tool_name":"calculate_force","description":"Computes net force from mass and acceleration with Newton's second law, reported in newtons, kilonewtons and pounds-force, together with the object's weight under standard gravity.","use_when":"You know a mass and its acceleration (or deceleration) and need the net force, or you need an object's weight in newtons or pounds-force from its mass.","do_not_use_when":"You need the gravitational pull between two bodies (use gravitational-force), a spring force (use hookes-law) or the force in circular motion (use centripetal-force).","required_inputs":["mass_kg","acceleration_m_s2"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/physics/newtons-second-law","markdown":"https://tttkmbb.com/physics/newtons-second-law.md","schema":"https://tttkmbb.com/api/v1/calculators/newtons-second-law","api":"https://tttkmbb.com/api/v1/calculate/newtons-second-law"}},{"calculator_id":"kinetic-energy","entity_type":"calculator","name":"Kinetic Energy Calculator","category":"physics","tool_name":"calculate_kinetic_energy","description":"Computes the translational kinetic energy of a moving mass from KE = ½·m·v², reported in joules, kilojoules, kilowatt-hours and kilocalories.","use_when":"You need the energy of motion of an object of known mass and speed (vehicle, projectile, ball), for example to compare impact or braking energies.","do_not_use_when":"Rotation contributes significantly (rotational energy ½·I·ω² is not included), speeds approach the speed of light (relativistic formula needed), or you need energy from height (use potential-energy).","required_inputs":["mass_kg","velocity_m_s"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/physics/kinetic-energy","markdown":"https://tttkmbb.com/physics/kinetic-energy.md","schema":"https://tttkmbb.com/api/v1/calculators/kinetic-energy","api":"https://tttkmbb.com/api/v1/calculate/kinetic-energy"}},{"calculator_id":"potential-energy","entity_type":"calculator","name":"Potential Energy Calculator","category":"physics","tool_name":"calculate_potential_energy","description":"Computes the gravitational potential energy of a mass raised to a height near a planet's surface with PE = m·g·h (standard gravity by default), and the speed the mass would reach if it fell that height freely.","use_when":"You need the energy stored by lifting a mass to a height, the minimum work to lift it, or the energy released when it falls (lifted loads, pumped hydro, dropped objects).","do_not_use_when":"Heights are a significant fraction of the planet's radius (g is not constant; use gravitational-force), or you need elastic energy (use hookes-law) or energy of motion (use kinetic-energy).","required_inputs":["mass_kg","height_m"],"optional_inputs":["gravity_m_s2"],"urls":{"html":"https://tttkmbb.com/physics/potential-energy","markdown":"https://tttkmbb.com/physics/potential-energy.md","schema":"https://tttkmbb.com/api/v1/calculators/potential-energy","api":"https://tttkmbb.com/api/v1/calculate/potential-energy"}},{"calculator_id":"work-power","entity_type":"calculator","name":"Work & Power Calculator","category":"physics","tool_name":"calculate_work_and_power","description":"Computes the mechanical work done by a constant force over a displacement, allowing for the angle between force and motion, and the average power when the duration is 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force needed to bring the object to rest (impulse–momentum theorem).","use_when":"You need an object's momentum, or the average force involved in stopping or launching it over a known time (collisions, braking, catching a ball).","do_not_use_when":"You need the outcome of a two-body collision (conservation of momentum between two objects is not implemented), or only the energy of motion (use kinetic-energy).","required_inputs":["mass_kg","velocity_m_s"],"optional_inputs":["stop_time_s"],"urls":{"html":"https://tttkmbb.com/physics/momentum","markdown":"https://tttkmbb.com/physics/momentum.md","schema":"https://tttkmbb.com/api/v1/calculators/momentum","api":"https://tttkmbb.com/api/v1/calculate/momentum"}},{"calculator_id":"free-fall","entity_type":"calculator","name":"Free Fall Calculator","category":"physics","tool_name":"calculate_free_fall","description":"Computes the time to fall a given height from rest, or the height fallen in a given time, together with the final (impact) velocity, using h = ½·g·t² with no air resistance.","use_when":"An object is dropped from rest near a planet's surface and you need how long it falls, how far, or how fast it lands (a dropped tool, a stone in a well).","do_not_use_when":"Air drag matters (light or fast objects, skydivers, long falls near terminal velocity), the object has an initial velocity or launch angle (use projectile-motion), or heights are comparable to the planet's radius.","required_inputs":[],"optional_inputs":["height_m","time_s","gravity_m_s2"],"urls":{"html":"https://tttkmbb.com/physics/free-fall","markdown":"https://tttkmbb.com/physics/free-fall.md","schema":"https://tttkmbb.com/api/v1/calculators/free-fall","api":"https://tttkmbb.com/api/v1/calculate/free-fall"}},{"calculator_id":"projectile-motion","entity_type":"calculator","name":"Projectile Motion Calculator","category":"physics","tool_name":"calculate_projectile_motion","description":"Computes time of flight, horizontal range, maximum height and impact speed for a projectile launched at a given speed and angle from an optional initial height, ignoring air resistance (closed-form kinematics).","use_when":"You need where and when a thrown, kicked or fired object lands on level ground, or its peak height, from launch speed and angle (and launch height).","do_not_use_when":"Air drag is significant (golf balls, bullets, shuttlecocks), the landing point is higher than the launch point, or the object is simply dropped (use free-fall).","required_inputs":["initial_speed_m_s","angle_degrees"],"optional_inputs":["initial_height_m","gravity_m_s2"],"urls":{"html":"https://tttkmbb.com/physics/projectile-motion","markdown":"https://tttkmbb.com/physics/projectile-motion.md","schema":"https://tttkmbb.com/api/v1/calculators/projectile-motion","api":"https://tttkmbb.com/api/v1/calculate/projectile-motion"}},{"calculator_id":"ohms-law","entity_type":"calculator","name":"Ohm's Law 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electricity-cost).","required_inputs":["voltage_v"],"optional_inputs":["current_a","power_w","usage_hours","price_per_kwh"],"urls":{"html":"https://tttkmbb.com/physics/electric-power","markdown":"https://tttkmbb.com/physics/electric-power.md","schema":"https://tttkmbb.com/api/v1/calculators/electric-power","api":"https://tttkmbb.com/api/v1/calculate/electric-power"}},{"calculator_id":"density-mass-volume","entity_type":"calculator","name":"Density Calculator","category":"physics","tool_name":"solve_density","description":"Solves ρ = m / V for whichever of density, mass or volume is omitted, and reports density in kg/m³ and g/cm³, volume in litres and cm³, and the specific gravity relative to water.","use_when":"You know two of mass, volume and density of an object or substance and need the third, e.g. the mass of a steel block, the volume of a litre of oil, or whether an object floats.","do_not_use_when":"The substance is a gas whose density depends strongly on pressure and temperature (use ideal-gas-law), or you need the volume of a shape first (use sphere, cylinder or rectangular-prism).","required_inputs":[],"optional_inputs":["mass_kg","volume_m3","density_kg_m3"],"urls":{"html":"https://tttkmbb.com/physics/density-mass-volume","markdown":"https://tttkmbb.com/physics/density-mass-volume.md","schema":"https://tttkmbb.com/api/v1/calculators/density-mass-volume","api":"https://tttkmbb.com/api/v1/calculate/density-mass-volume"}},{"calculator_id":"pressure-force-area","entity_type":"calculator","name":"Pressure Calculator","category":"physics","tool_name":"calculate_pressure","description":"Computes pressure as force divided by the area it acts on, and reports it in pascals, kilopascals, bar, pounds per square inch and standard atmospheres.","use_when":"You know a force (or a weight in newtons) and the contact area and need the pressure: a load on a footing, a hydraulic piston, a heel on a floor.","do_not_use_when":"You need fluid pressure at depth (P = ρ·g·h is not implemented), gas pressure from temperature and amount (use ideal-gas-law), or the force from a mass first (use force).","required_inputs":["force_n","area_m2"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/physics/pressure-force-area","markdown":"https://tttkmbb.com/physics/pressure-force-area.md","schema":"https://tttkmbb.com/api/v1/calculators/pressure-force-area","api":"https://tttkmbb.com/api/v1/calculate/pressure-force-area"}},{"calculator_id":"wavelength-frequency","entity_type":"calculator","name":"Wavelength & Frequency Calculator","category":"physics","tool_name":"convert_wavelength_frequency","description":"Converts between wavelength and frequency for a wave of known propagation speed (default: the speed of light in vacuum) and, for electromagnetic waves in vacuum, reports the photon energy E = h·f in joules and electronvolts.","use_when":"You know either the wavelength or the frequency of a light, radio or sound wave and need the other, or you need the photon energy of light of a given wavelength.","do_not_use_when":"The wave travels in a dispersive medium (glass, water) unless you supply the correct phase speed, or you need Doppler shifts or refraction.","required_inputs":[],"optional_inputs":["wavelength_m","frequency_hz","wave_speed_m_s"],"urls":{"html":"https://tttkmbb.com/physics/wavelength-frequency","markdown":"https://tttkmbb.com/physics/wavelength-frequency.md","schema":"https://tttkmbb.com/api/v1/calculators/wavelength-frequency","api":"https://tttkmbb.com/api/v1/calculate/wavelength-frequency"}},{"calculator_id":"pendulum","entity_type":"calculator","name":"Pendulum Period Calculator","category":"physics","tool_name":"calculate_pendulum_period","description":"Computes the period, frequency and angular frequency of a simple pendulum from its length with the small-angle formula T = 2π√(L/g); when an amplitude is given it also returns the exact period from the arithmetic–geometric mean.","use_when":"You need how long a pendulum of known length takes to swing on Earth or another body, or how much a large swing angle lengthens the period.","do_not_use_when":"The bob's size or the rod's mass is not negligible (physical pendulum, T = 2π√(I / (m·g·d))), or the oscillator is a mass on a spring (use hookes-law).","required_inputs":["length_m"],"optional_inputs":["gravity_m_s2","amplitude_degrees"],"urls":{"html":"https://tttkmbb.com/physics/pendulum","markdown":"https://tttkmbb.com/physics/pendulum.md","schema":"https://tttkmbb.com/api/v1/calculators/pendulum","api":"https://tttkmbb.com/api/v1/calculate/pendulum"}},{"calculator_id":"hookes-law","entity_type":"calculator","name":"Hooke's Law Calculator","category":"physics","tool_name":"calculate_hookes_law","description":"Computes the restoring force of a linear spring and the elastic potential energy stored at a given displacement, plus the natural period and frequency of a mass on that spring when a mass is supplied.","use_when":"You know a spring constant and how far the spring is stretched or compressed and need the force or stored energy, or the oscillation period of a spring–mass system.","do_not_use_when":"The spring is loaded beyond its elastic (linear) limit, or you need gravitational energy (use potential-energy) or a pendulum's period (use pendulum).","required_inputs":["spring_constant_n_m","displacement_m"],"optional_inputs":["mass_kg"],"urls":{"html":"https://tttkmbb.com/physics/hookes-law","markdown":"https://tttkmbb.com/physics/hookes-law.md","schema":"https://tttkmbb.com/api/v1/calculators/hookes-law","api":"https://tttkmbb.com/api/v1/calculate/hookes-law"}},{"calculator_id":"gravitational-force","entity_type":"calculator","name":"Gravitational Force Calculator","category":"physics","tool_name":"calculate_gravitational_force","description":"Computes the attractive gravitational force between two point or spherically symmetric masses at a given centre-to-centre distance with Newton's law and the CODATA 2018 value of G, plus the acceleration each mass experiences.","use_when":"You need the gravitational pull between two bodies (planet and satellite, star and planet, two laboratory masses) or the surface gravity of a body from its mass and radius.","do_not_use_when":"You only need weight near Earth's surface (use force with 9.80665 m/s²), or relativistic effects matter (near black holes, precision orbits).","required_inputs":["mass1_kg","mass2_kg","distance_m"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/physics/gravitational-force","markdown":"https://tttkmbb.com/physics/gravitational-force.md","schema":"https://tttkmbb.com/api/v1/calculators/gravitational-force","api":"https://tttkmbb.com/api/v1/calculate/gravitational-force"}},{"calculator_id":"centripetal-force","entity_type":"calculator","name":"Centripetal Force Calculator","category":"physics","tool_name":"calculate_centripetal_force","description":"Computes the centripetal (centre-seeking) force and acceleration needed to keep a mass moving in a circle of given radius at a given speed, plus the angular velocity, rotation period and rpm.","use_when":"You need the force on a car in a bend, a mass on a string, a satellite or a centrifuge sample from mass, tangential speed and radius, or the g-load of circular motion.","do_not_use_when":"You know the angular speed (rpm) rather than the tangential speed (compute v = ω·r first), or the motion is not circular at constant speed.","required_inputs":["mass_kg","velocity_m_s","radius_m"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/physics/centripetal-force","markdown":"https://tttkmbb.com/physics/centripetal-force.md","schema":"https://tttkmbb.com/api/v1/calculators/centripetal-force","api":"https://tttkmbb.com/api/v1/calculate/centripetal-force"}},{"calculator_id":"specific-heat","entity_type":"calculator","name":"Specific Heat Calculator","category":"physics","tool_name":"calculate_specific_heat_energy","description":"Computes the heat energy needed to change the temperature of a mass of material by a given amount from Q = m·c·ΔT, using the specific heat capacity of liquid water (4186 J/(kg·K)) by default.","use_when":"You need how much energy heats or cools a known mass of water, metal or another substance by a given number of degrees, without a phase change.","do_not_use_when":"The substance melts, boils or freezes within the range (latent heat is not included), or you need the final temperature when two bodies are mixed (calorimetry is not implemented).","required_inputs":["mass_kg","temperature_change_k"],"optional_inputs":["specific_heat_j_kg_k"],"urls":{"html":"https://tttkmbb.com/physics/specific-heat","markdown":"https://tttkmbb.com/physics/specific-heat.md","schema":"https://tttkmbb.com/api/v1/calculators/specific-heat","api":"https://tttkmbb.com/api/v1/calculate/specific-heat"}},{"calculator_id":"resistors-series-parallel","entity_type":"calculator","name":"Resistors in Series and Parallel 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ohms-law).","required_inputs":["resistances_ohm"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/physics/resistors-series-parallel","markdown":"https://tttkmbb.com/physics/resistors-series-parallel.md","schema":"https://tttkmbb.com/api/v1/calculators/resistors-series-parallel","api":"https://tttkmbb.com/api/v1/calculate/resistors-series-parallel"}}]},"timestamp":"2026-09-23T23:27:38Z","next_actions":[],"links":{"docs":"https://tttkmbb.com/calculators.md"}}