To determine the centroid of the object first moment of area is used.
To predict the resistance of a shape to bending and deflection which are directly proportional, second moment of area is used.
Answer:

we can see that this time period is independent of the mass of the child so answer would be same if the child mass is different
Explanation:
Natural frequency of a simple pendulum of L length is given as

so the time period of the oscillation is given as

so we will have



also from above formula we can see that this time period is independent of the mass of the child so answer would be same if the child mass is different
Answer:
The answer is D or Fertilizer, sorry for the late answer
Explanation:
Answer:
yes
Explanation: Work is done when there is movement. Therefore it was work was being done.