Mollusks live
in fresh water, in marine environment, but also on land.
<span>Echinoderms
live only in water. This is the reason why they have developed different
systems for moving. Mollusks have only singular muskullus foot for walking and
Echinoderms have tube feet which they use for moving, as well for collecting
and transporting food to their mouth. </span>
I’ll say c Bc it make more since to find the travel distance
The boundary between the crust and mantle is marked by a seismic-velocity discontinuity is called Mohorovicic discontinuity.
Mohorovicic discontinuity was discovered by Andrija Mohorovicic in 1909 who was a Croatian seismologist. He realized that the velocity of a seismic wave is related to the material's density where it is moving through. He decoded that the acceleration of the seismic waves that are observed within outer shell of the earth is a compositional change. Thus, the acceleration should be caused by a material of higher density.
Answer:

Explanation:
The force of kinetic friction on the block is defined as:

Where
is the coefficient of kinetic friction between the block and the surface and N is the normal force, which is always perpendicular to the surface that the object contacts. So, according to the free body diagram of the block, we have:

Replacing this in the first equation and solving for
:

Convert 10mm to metres = 0.01m
Wave speed = frequency *wavelength
= 4Hz*0.01m
= 0.04 m/s
Hope this helps