A motion at a constant speed is called uniform motion.
A car moves at a constant speed on a straight path. At certain points travel time and traveled distance are measured and recorded.
\( s \) in \( \rm m \) | |||||||
\( t \) in \( \rm s \) | |||||||
\( v \) in \( \rm \frac{m}{s} \) |
The distance-time curve is a straight line passing through the origin. This shows that the way and the time are proportional to each other.
The proportionality constant is obviously the velocity \(v \) of the body.
$$ v = \dfrac{s}{t} $$The speed-time curve is a straight line parallel to the X axis. This shows that the velocity remains the same throughout the journey. The following applies:
$$ v = \text{const.} $$To specify the velocity the units \(\rm \frac{m}{s} \) and \(\rm \frac{km}{h} \) are often used. They can be converted into each other as follows:
$$ \rm 1 \,\, \dfrac{km}{h} = \dfrac{1000 \,\, m}{3600 \,\, s} = \dfrac{5}{18} \dfrac{m}{s} $$