When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Thunder - Wikipedia

    en.wikipedia.org/wiki/Thunder

    The most noticeable aspect of lightning and thunder is that the lightning is seen before the thunder is heard. This is a consequence of the speed of light being much greater than the speed of sound. The speed of sound in dry air is approximately 343 m/s (1,130 ft/s) or 1,236 km/h (768 mph) at 20 °C (68 °F; 293 K). [19]

  3. Speed of sound - Wikipedia

    en.wikipedia.org/wiki/Speed_of_sound

    The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. More simply, the speed of sound is how fast vibrations travel. At 20 °C (68 °F), the speed of sound in air, is about 343 m/s (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn), or 1 km in 2.91 s or one mile in 4.69 s.

  4. Lightning - Wikipedia

    en.wikipedia.org/wiki/Lightning

    Positive lightning is less common than negative lightning and on average makes up less than 5% of all lightning strikes. [ 10 ] A bolt from the blue lightning strike which appears to initiate from the clear, but [ clarification needed ] the turbulent sky above the anvil cloud and drive a bolt of plasma through the cloud directly to the ground.

  5. Mach number - Wikipedia

    en.wikipedia.org/wiki/Mach_number

    c is the speed of sound in the medium, which in air varies with the square root of the thermodynamic temperature. By definition, at Mach 1, the local flow velocity u is equal to the speed of sound. At Mach 0.65, u is 65% of the speed of sound (subsonic), and, at Mach 1.35, u is 35% faster than the speed of sound (supersonic).

  6. Lightning strike - Wikipedia

    en.wikipedia.org/wiki/Lightning_strike

    The flash of a lightning strike and resulting thunder occur at roughly the same time. But light travels 300,000 km/sec, almost a million times the speed of sound. Sound travels at the slower speed of about 340 m/sec (depending on the temperature), so the flash of lightning is seen before thunder is heard. A method to determine the distance ...

  7. Hypersonic speed - Wikipedia

    en.wikipedia.org/wiki/Hypersonic_speed

    Simulation of hypersonic speed (Mach 5) While the definition of hypersonic flow can be quite vague and is generally debatable (especially because of the absence of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow.

  8. Study finds shocking benefit of lightning - AOL

    www.aol.com/study-finds-shocking-benefit...

    What is the purpose of lightning? That might sound like a deeply philosophical question, but scientists may have shed some more light on the answer with the results of a recently released study.

  9. Orders of magnitude (speed) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(speed)

    Speed of International Space Station and typical speed of other satellites such as the Space Shuttle in low Earth orbit. 7,777: 28,000: 17,400: 2.594 × 10 −5: Speed of propagation of the explosion in a detonating cord. 10 4: 10,600 38,160 23,713.65 0.00004 Speed of propagation of the explosion of Octanitrocubane (ONC). 11,107: 39,985.2: ...