Earth's Velocity to Velocity of Sound in Pure Water

Earth's orbital velocity around the Sun is approximately 29,765 m/s (29.8 km/s), the speed at which our planet travels through space.

v = 2πr/T where r is Earth's orbital radius (~150 million km) and T is one year. Result: ~29.8 km/s.

To km/h: × 3,600. To mph: × 66,600. 29.8 km/s = 107,280 km/h = 66,660 mph.

Interplanetary mission Δv calculations, understanding Earth's motion, and cosmic velocity references.

We're all traveling at ~30 km/s around the Sun right now. In one second, Earth moves 30 km — about 19 miles!

Forgetting about Earth's motion when calculating interplanetary trajectories — it provides free velocity!

~30 km/s around the Sun. We travel 940 million km per year at this speed. Missions to other planets add/subtract from this.

The speed of sound in pure water at 20°C is approximately 1,482.7 m/s, significantly faster than in air due to water's higher density and bulk modulus.

Depends on water temperature, salinity, and pressure. At 20°C, pure water: ~1,483 m/s. Varies with depth and location.

To km/h: × 3.6. To ft/s: × 3.281. 1,483 m/s = 5,339 km/h = 3,317 mph.

Sonar (submarine detection, fish finding), ultrasound imaging, underwater communication, and oceanographic measurements.

Sound in water travels ~4.3× faster than in air. Whales can communicate over hundreds of km using this. SOFAR channel enables even longer distances.

Assuming sound speed in water equals sound in air — it's much faster. Also, forgetting temperature dependence.

~1,500 m/s in water (rule of thumb). 4–5× faster than in air. Increases with temperature, salinity, and depth.