Search results
Results from the WOW.Com Content Network
The Mach number (M or Ma), often only Mach, (/ m ɑː k /; German:) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. [1] [2] It is named after the Austrian physicist and philosopher Ernst Mach. =, where: M is the local Mach number,
In aerodynamics, a hypersonic speed is one that exceeds five times the speed of sound, often stated as starting at speeds of Mach 5 and above. [1] The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since individual physical changes in the airflow (like molecular dissociation and ionization) occur at ...
[4] [5] Most modern firearm bullets are supersonic, with rifle projectiles often travelling at speeds approaching and in some cases [6] well exceeding Mach 3. Most spacecraft are supersonic at least during portions of their reentry, though the effects on the spacecraft are reduced by low air densities. During ascent, launch vehicles generally ...
Friday, April 22nd marks Earth Day 2022, and while we’re not limiting our pledge to live a little greener to a single day a year, it marks a great opportunity to teach our kids about living ...
Monday, April 22nd marks Earth Day 2024, and while we aren’t limiting our pledge to live a little greener to a single day, it’s a great opportunity to teach our kids about living sustainably. ...
Dimensionless numbers (or characteristic numbers) have an important role in analyzing the behavior of fluids and their flow as well as in other transport phenomena. [1] They include the Reynolds and the Mach numbers, which describe as ratios the relative magnitude of fluid and physical system characteristics, such as density, viscosity, speed of sound, and flow speed.
Themed “Our Shared Home,” this year’s Call to Earth Day focuses on bridging the gap between humans and wildlife. Over 200,000 participants, including 235 schools, took part this year.
Mach number, a useful quantity in aerodynamics, is the ratio of air speed to the local speed of sound. At altitude, for reasons explained, Mach number is a function of temperature. Aircraft flight instruments, however, operate using pressure differential to compute Mach number, not temperature. The assumption is that a particular pressure ...