Distance

As a distance the length of which is on surface of the earth covered path of a pedestrian or vehicle , respectively. It is to be differentiated from the horizontal route , includes deviations from the straight route (i.e. detours ) and also the height differences occurring along the way . In a broader sense, the path can also lead through three-dimensional space (for example the trajectory of an electron, free path in particle physics).

In the case of a movement at constant speed , the distance covered from a point in time to a point in time is obtained by multiplying the speed by the time span : ${\ displaystyle t_ {1}}$ ${\ displaystyle t_ {2}}$ ${\ displaystyle s_ {12}}$ ${\ displaystyle v}$ ${\ displaystyle t_ {12} = t_ {2} -t_ {1}}$

{\ displaystyle s_ {12} = v \ cdot t_ {12}}

.

In the case of uneven movement, for example due to a section of the path with a gradient, this equation must be applied individually for each section, for which additional points in time must be measured. The distances determined in this way are summarized by adding them to the total distance covered (see Path (physics) ).

The distance can be measured in different ways:

with a measuring wheel (Odometer, Peiselerrad)

by inertial navigation of a gyro platform

with the odometer of a vehicle

with the step counter if you know the step length

from the travel time of a pedestrian if his speed is known - see travel hour

by evaluating satellite navigation .

Distance measurement in nautical and aviation

In shipping, due to currents and winds, a distinction must be made between travel through water and travel over the ground . The former is measured using logging , the latter using electrical or radio methods.

The same applies to aviation : the airspeed is measured with so-called airspeed indicators , those over the ground (or the distance covered) with Doppler radar or other navigation methods .

Individual evidence

^ Helmut Lindner: Physics for Engineers . 12th edition. Vieweg & Sohn, 1991, ISBN 978-3-528-64047-7 , pp. 34 ( limited preview in Google Book search).

[1] Helmut Lindner: Physics for Engineers . 12th edition. Vieweg & Sohn, 1991, ISBN 978-3-528-64047-7 , pp. 34 ( limited preview in Google Book search).