Answer:
The mass of the products and reactants are the same on both sides of the equation.
The number of atoms of products and reactants are equal and hence it proves the law of conservation of mass.
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Answer:

Explanation:
Given that,
The spring constant of spring 1, 
The motion of the object on spring 1 has twice the amplitude as the motion of the object on spring 2, 
As the magnitude of the maximum velocity is the same in each case, it means the maximum kinetic energy is same in each case. In other words, the total energy is same.




So, the spring constant of spring 2 is 920 N/m. Hence, this is the required solution.