Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
Answer : The 
must be administered.
Solution :
As we are given that a vial containing radioactive selenium-75 has an activity of 
.
As, 3.0 mCi radioactive selenium-75 present in 1 ml
So, 2.6 mCi radioactive selenium-75 present in 
Conversion :
Therefore, the must be administered.
Mechanical Energy
Mechanism energy is the energy associated with the position and motion of an object. Therefore it is also the summation of the kinetic and potential energies of the object.
Explanation:
Mechanism energy is the energy associated with the position and motion of an object. Therefore it is also the summation of the kinetic and potential energies of the object.
In the muscles, to have movement, the chemical bonds in ATP is broken to enable the sliding action of the myosin and actin fibres of a sarcomere (the basic unit of muscle). This sliding action is responsible for contraction of muscle. The coordinated contractions and relaxations of sarcomeres on muscles result in movement which translates to mechanical energy.
This process is never 100% efficient with some energy lost as heat energy.
Learn More:
For more on energy transformation check out;
brainly.com/question/12764386
brainly.com/question/12841537
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It would be mol/dm^3
Formula of concentration: (no. of moles/volume of solution in dm^3)
1 cm^3 = 0.001dm^3
Hope this helped. :)
