A. is the answer for this question
Since static friction is the minimum force required to just start the motion of a stationary object.
Here if we need to start an object from rest then we required F = 700 N
So for the first part of the above problem Force will be F = 700 N
Now if the box is already moving then we will have to use kinetic friction force between box and floor
now we can write the equation of net force as

here



now we will have


????????????? ??????????????????? ?????????????????
Answer:
First statement:
Energy can neither be created nor destroyed.
Second statement:
Energy can be converted from one form to another.
Explanation:
According to the law of conservation of energy:energy can neither be created nor destroyed but can be converted from one form to another