They has been very successful but they are very expensive to operate that is your answer I hope this helps
The time for the echo to return is directly proportional to the distance. vw = fλ. In a given medium under fixed conditions, vw is constant, so that there is a relationship between f and λ; the higher the frequency, the smaller the wavelength.
For an inelastic collision where coefficient of restitution,e, is equal to 0, the momentum is conserved but not the kinetic energy. So, there is addition or elimination of kinetic energy.
On the otherhand, when e = 1, like for an elastic collision, kinetic energy and momentum is conserved. Thus, the system's kinetic energy is unchanged.
Answer : The volume of a sample of 4.00 mol of copper is 
Explanation :
First we have to calculate the mass of copper.


Now we have to calculate the volume of copper.
Formula used :

Now put all the given values in this formula, we get:


Conversion used :

Therefore, the volume of a sample of 4.00 mol of copper is 