Answer: it would be A
Explanation: how are we to measure the air of a square mile
To solve this problem it is necessary to apply the concepts related to Newton's second law, the definition of density and the geometric relationships that allow us to find the volume of the figures presented.
For the particular case of the Cube with equal sides its volume is determined by


In the case of perforated material we have that its volume is given according to the cylindrical geometry, that is to say



In this way the net volume would be



We need to find the mass, but we have the Weight and Gravity so from Newton's second Law




PART A) From the relation of density as a unit of mass and volume we have to



PART B) To find the weight of the cube then we apply the ratio of




Answer:
Part a)
T = 3.96 s
Part b)
T = 1.98 s
Part c)
T = 2.8 s
Explanation:
As we know that time period of spring block system is given as

T = 2.8 s
Part a)
If the mass of the block attached is doubled
then we will have



Part b)
If the spring constant is doubled
then we have



Part c)
If the amplitude is halved but mass and spring constant will remain the same
so here we know that time period does not depends on Amplitude
so we will have

T = 2.8 s
Answer:
Im pretty sure its B im very sorry if its wrong.