Search results
Results from the WOW.Com Content Network
A vehicle accelerating from a stop travels this distance in time t i = √ 2d i ⁄ a i while through traffic travels a distance equal to their speed multiplied by that time. The time t pc , for the stopped motorist, is the sum of perception time and the time required to actuate an automatic transmission or shift to first gear which is usually ...
An electromagnetic wave propagating along a path C has the phase shift over C as if it was propagating a path in a vacuum, length of which, is equal to the optical path length of C. Thus, if a wave is traveling through several different media, then the optical path length of each medium can be added to find the total optical path length.
The design sight distance allows a below-average driver to stop in time to avoid a collision in most cases. Driver perception/reaction distance is calculated by: d PRT = 0.278 Vt (metric) d PRT = 1.47 Vt (US customary) Where: d PRT = driver perception-reaction distance, m (ft) V = design speed, km/h (mph) t = brake reaction time, in seconds
In electromagnetics, especially in optics, beam divergence is an angular measure of the increase in beam diameter or radius with distance from the optical aperture or antenna aperture from which the beam emerges. The term is relevant only in the "far field", away from any focus of the beam. Practically speaking, however, the far field can ...
Assuming a perfect sphere with no terrain irregularity, the distance to the horizon from a high altitude transmitter (i.e., line of sight) can readily be calculated. Let R be the radius of the Earth and h be the altitude of a telecommunication station. The line of sight distance d of this station is given by the Pythagorean theorem;
When light shines on the circular obstacle, Huygens' principle says that every point in the plane of the obstacle acts as a new point source of light. The light coming from points on the circumference of the obstacle and going to the center of the shadow travels exactly the same distance, so all the light passing close by the object arrives at ...
The distance (or perpendicular distance) from a point to a line is the shortest distance from a fixed point to any point on a fixed infinite line in Euclidean geometry. It is the length of the line segment which joins the point to the line and is perpendicular to the line. The formula for calculating it can be derived and expressed in several ways.
The resistance distance between vertices and is proportional to the commute time, of a random walk between and .The commute time is the expected number of steps in a random walk that starts at , visits , and returns to .