enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Mach number - Wikipedia

    en.wikipedia.org/wiki/Mach_number

    It is first determined whether M is indeed greater than 1.0 by calculating M from the subsonic equation. If M is greater than 1.0 at that point, then the value of M from the subsonic equation is used as the initial condition for fixed point iteration of the supersonic equation, which usually converges very rapidly. [ 8 ]

  3. Hydraulic jumps in rectangular channels - Wikipedia

    en.wikipedia.org/wiki/Hydraulic_Jumps_in...

    1. y 2 /y 1 > 1: depth increases over the jump so that y 2 > y 1 2. Fr 2 < 1: downstream flow must be subcritical 3. Fr 1 > 1: upstream flow must be supercritical. Table 2 shows the calculated values used to develop Figure 8. The values associated with a y 1 = 1.5 ft are not valid for use since they violate the above limits.

  4. Orders of magnitude (length) - Wikipedia

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

    1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4 ft 8 12 in; 2.5 m – distance from the floor to the ceiling in an average residential house [119] 2.7 m – length of the Starr Bumble Bee II, the smallest plane; 2.77–3.44 m – wavelength of the broadcast radio FM band 87–108 MHz

  5. Peak ground acceleration - Wikipedia

    en.wikipedia.org/wiki/Peak_ground_acceleration

    Peak ground acceleration can be expressed in fractions of g (the standard acceleration due to Earth's gravity, equivalent to g-force) as either a decimal or percentage; in m/s 2 (1 g = 9.81 m/s 2); [7] or in multiples of Gal, where 1 Gal is equal to 0.01 m/s 2 (1 g = 981 Gal).

  6. f-number - Wikipedia

    en.wikipedia.org/wiki/F-number

    Most modern lenses use a standard f-stop scale, which is an approximately geometric sequence of numbers that corresponds to the sequence of the powers of the square root of 2: f /1, f /1.4, f /2, f /2.8, f /4, f /5.6, f /8, f /11, f /16, f /22, f /32, f /45, f /64, f /90, f /128, etc. Each element in the sequence is one stop lower than the ...

  7. Noise reduction coefficient - Wikipedia

    en.wikipedia.org/wiki/Noise_reduction_coefficient

    This rating is common of thicker, porous sound absorptive materials such as 2-inch-thick (51 mm) fabric-wrapped fiberglass panel. Materials can achieve NRC values greater than 1.00. This is a shortcoming of the test procedure and a limitation of how acousticians define a square unit of absorption, and not a characteristic of the material itself.

  8. Decibel - Wikipedia

    en.wikipedia.org/wiki/Decibel

    The decibel originates from methods used to quantify signal loss in telegraph and telephone circuits. Until the mid-1920s, the unit for loss was miles of standard cable (MSC). 1 MSC corresponded to the loss of power over one mile (approximately 1.6 km) of standard telephone cable at a frequency of 5000 radians per second (795.8 Hz), and matched closely the smallest attenuation detectable to a ...

  9. Friction - Wikipedia

    en.wikipedia.org/wiki/Friction

    While in most relevant applications μ < 1, a value above 1 merely implies that the force required to slide an object along the surface is greater than the normal force of the surface on the object. For example, silicone rubber or acrylic rubber -coated surfaces have a coefficient of friction that can be substantially larger than 1.