Physics

Find the speed of uniform motion from distance and time using v = d / t. Choose meters or kilometers and seconds, minutes, or hours, and read the result in both m/s and km/h.

Find the distance traveled in uniform motion from speed and time using d = v × t, with unit conversion for m/s, km/h, and seconds, minutes, hours.

Find the travel time for motion at constant speed from distance and velocity. Time equals distance divided by speed, shown in seconds, minutes, and hours.

Find the true average speed of a round trip over equal distances from your outbound and return speeds, using the harmonic mean.

Find centrifugal force F=mv²/r=mrω² from mass, radius and speed (or angular velocity), plus centripetal acceleration, angular velocity and rotation period.

Convert between rpm, angular velocity, linear speed, and period. From a radius, also get linear speed and centripetal acceleration.

Find the acceleration of uniformly accelerated linear motion from initial velocity, final velocity, and time. Also shows distance and average velocity.

Find the time and distance for uniformly accelerated motion from initial velocity, final velocity, and acceleration.

Enter any two of torque, rotational speed and power to find the third, with angular velocity plus kW and PS conversions.

Find free fall distance and speed from the fall time. With initial speed zero and gravity g=9.80665 m/s squared, it gives distance, speed in m/s and km/h, and kinetic energy per mass.

Find the fall time and impact speed of a free fall from the drop distance, using g=9.80665 m/s² and ignoring air resistance.

Find the fall time and fall distance from an impact velocity in free fall. Uses gravity g = 9.80665 m/s squared with t = v / g and d = v squared / (2g).

From mass and drop height, compute potential energy, kinetic energy at impact, and impact speed.

Compute falling speed and distance with air resistance from mass, terminal speed, and elapsed time. Shows the fraction of terminal speed reached and the difference from a vacuum.

From terminal velocity and fall distance, compute the impact speed and time with air resistance, and compare with a vacuum drop.

Find the range, maximum height, flight time, and velocity components from initial speed and launch angle.

Find the launch speed and angle from a known peak height and horizontal range, with flight time and a trajectory sketch.

From initial speed, launch angle, and elapsed time, find the position (x, y) and velocity at that instant, with a trajectory sketch.

Enter the flight time and horizontal range to back-calculate the launch speed, launch angle, and peak height for ideal projectile motion without air resistance.

Find the launch speed, peak height, and flight time from a launch angle and horizontal range, with a trajectory sketch.

Find the launch speed, range, and flight time from the launch angle and maximum height. Shows the trajectory.

From launch speed, launch angle, and the height difference between launch and landing, compute horizontal range, time of flight, peak height, and landing speed.

Enter the peak height, horizontal range, and height difference to back out the launch speed, launch angle, and flight time, with a sketch of the trajectory.

Compute a simple pendulum period T=2π√(L/g) from length and gravity, plus frequency, angular frequency, and a large-amplitude correction.

Vary the string length over a range and step to list the simple pendulum period T=2π√(L/g) and frequency in a table. Set length range, step, and gravity.

Compute the displacement at a given time, the damping regime, and the Q factor from the natural angular frequency and damping coefficient.

Compute the steady-state amplitude, phase lag, resonance angular frequency, and Q factor of a driven damped oscillator, with a resonance curve.

Calculate the escape velocity needed to break free from a planet or star from its mass and radius. Pick a preset such as Earth, the Moon, Mars, Jupiter or the Sun, or enter your own values, and also get the orbital velocity and surface gravity.

Compute orbital speed, period, orbit radius, and angular speed for a circular satellite orbit from altitude. Works for other bodies too.

Convert a calendar year, month, day, and time into the Julian Day (JD) and Modified Julian Day (MJD) used in astronomy. Also shows the weekday, day of year, and integer Julian day number.

Enter a Julian Day (JD) to convert it to a Gregorian calendar date, time (UTC), weekday, and Modified Julian Day (MJD).

Calculate sunrise, solar noon, and sunset times, day length, and the sun's noon altitude from latitude, longitude, date, and time zone using the NOAA solar position algorithm.

Compute the Sun altitude and azimuth for any moment from latitude, longitude, date, time and time zone. Also returns declination, hour angle and noon altitude.

From a date plus latitude, longitude and time zone, compute the solar noon time, noon altitude, equation of time and solar declination, with an equation of time curve.

Enter a date to find the moon age, the moon phase (new moon, first quarter, full moon, last quarter and more), the illuminated fraction, and the days until the next full and new moon, with a diagram of the lit moon.

Compute the tidal acceleration the Moon and Sun exert on Earth via a=2GMr/d3, with the Moon to Sun tidal ratio and spring and neap combinations.

Convert station pressure to sea-level pressure from elevation and temperature using the standard atmospheric reduction formula.

Estimate altitude from local and sea-level pressure using the standard atmosphere barometric formula, with optional temperature input.

Compute air pressure at a given altitude from sea level pressure and temperature using the standard atmosphere formula, plus pressure ratio and boiling point drop.

Find how far the horizon is from your eye height. Includes the refraction-adjusted viewing distance and the maximum distance two objects of equal height can see each other.

Compute great-circle distance and bearing from two latitude and longitude points.

Compute the observed wavelength and frequency shift plus redshift z of light from a moving source using the relativistic Doppler effect.

Find the observed frequency and wavelength shift from source frequency, speed of sound, and source and observer speeds. Approach or recede.

Calculate the speed of sound in air from temperature. Shows m/s, km/h, Mach 1 reference, and time to travel 1 km.

Compute the speed of sound in seawater from temperature, salinity, and depth using the Mackenzie equation.

Compute decibels (dB) from an input and output value. Power ratios use 10 log10, while voltage, amplitude, and sound pressure ratios use 20 log10.

Convert a decibel value into a ratio. Power ratio is 10^(dB/10) and amplitude ratio is 10^(dB/20).

Find resistance from voltage and current using Ohms law R = V / I. It also computes power and conductance, with a simple circuit diagram.

Compute voltage V from current I and resistance R using Ohms law V=IR. It also derives power P=I squared R and shows a clear circuit diagram.

Find the current I=V/R flowing in a circuit from voltage V and resistance R. It also gives power P and conductance, with a circuit diagram.

Compute the capacitance C of a parallel plate capacitor from plate area, gap distance and relative permittivity. Add a voltage to also get stored charge, energy and field strength.

Enter several resistor values (comma separated) to compute the series total (sum) and parallel total (reciprocal of the sum of reciprocals), shown with a circuit diagram.

Compute the total capacitance of capacitors in series or parallel. Series uses the reciprocal sum, parallel uses the simple sum. Includes a circuit diagram.

Calculate the total inductance of coils (inductors) connected in series or parallel. Enter any number of inductance values separated by commas and view a circuit diagram.

Compute the AC impedance, inductive reactance, phase angle, and power factor of an RL series circuit from resistance R, inductance L, and frequency f.

Find the total impedance, inductive reactance, phase angle, and branch current ratio of an RL parallel circuit from resistance R, inductance L, and frequency f.

Calculate the impedance of a series LC circuit. Enter inductance, capacitance, and frequency to get the inductive and capacitive reactances, the magnitude of the combined impedance, and the resonant frequency.

Compute the AC impedance of a parallel LC circuit from inductance, capacitance, and frequency. The tool also returns the inductive reactance XL, capacitive reactance XC, and the resonant frequency.

From resistance R, capacitance C, and frequency f, compute the total impedance, capacitive reactance, phase angle, power factor, and cutoff frequency of an RC series circuit, with an impedance triangle.

Find the total impedance, capacitive reactance, phase angle, and cutoff frequency of a parallel RC circuit from resistance R, capacitance C, and frequency f.

Calculate the impedance of a series RLC circuit. Get reactances, phase angle, power factor, and resonant frequency.

Calculate the AC impedance, susceptance, phase angle, and resonant frequency of a parallel RLC circuit with a resistor, inductor, and capacitor.

From an EMF E and resistors R1 (series), R2 and R3 (parallel), compute the total resistance, total current, each resistor current and voltage, and total power.

Compute relativistic length contraction from a proper length and speed (m/s or speed-of-light ratio beta), including the Lorentz factor gamma.

Compute the observer elapsed time and Lorentz factor from speed and proper time.

Combine two velocities using the special relativity velocity addition formula w=(u+v)/(1+uv/c²). Enter speeds in m/s or as a fraction of light speed (β), and see the result, its c ratio, the difference from the classical sum, and the Lorentz factor.

From mass and speed (or velocity ratio β), compute the special-relativity total energy E=γmc², rest energy, kinetic energy, relativistic momentum, and the Lorentz factor γ.

From a body mass and distance from its center, compute the gravitational time dilation ratio t0/t using the Schwarzschild metric. See the Schwarzschild radius, yearly time loss, and the idea behind GPS clock corrections.

Enter the quantum numbers (n, l, m) and radius r (in Bohr radii a0) to compute the hydrogen radial wavefunction R_nl(r) and radial probability density, with energy level E_n and orbital name.

Compute the harmonic oscillator wavefunction ψ_n(ξ), probability density, and energy level from quantum number n and dimensionless position ξ, with a plotted waveform.

Compute the resonant frequency, Q factor, bandwidth, and characteristic impedance of a series RLC circuit from R, L, and C, with a resonance curve.