Answer:
In terms of distance, average speed is 20 km/h
In terms of displacement, average speed is 0 km/h.
Explanation:
Total distance:

Total time is 3.0 hours
but:

In terms of distance.
substitute:


In terms of displacement:

<span>Soil conservation involves protecting soil quality and preventing erosion.
Answer: A</span>
the relation that relates the speed of wave, frequency of wave and wavelength is given as
wavelength = 
the speed of wave in a medium remains constant. hence the wavelength is inversely related to the frequency of wave.
that means, as the frequency is increased, the wavelength decreases and vice versa.
hence the correct choice is
B decreases
Relative density, or specific gravity, is the ratio of the density of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest; for gases, the reference is air at room temperature.