Explanation:
Volume of 10 coins = 100ml - 75ml = 25ml
Volume of 1 coin = 25ml / 10 = 2.5ml
The average volume of each coin is 2.5ml.
<span>If only one force is acting an object it can have zero acceleration but it cannot have zero velocity. This occurs because acceleration is a change in speed, therefore when one force is acting upon the object the speed will remain constant. It can't have zero velocity because if one force is acting upon it then it is moving and no matter what that means it will have a velocity that isn't zero.</span>
This question involves the concepts of work done and elastic potential energy.
The work done by the spring when its extension changes from X to X/4 is "0.56 E".
The work done by the spring is equal to the elastic potential energy stored in the spring, which is given as follows:

where,
W = work done = ?
E = elastic potential energy
k = spring constant
X = extension
Now, the spring moves to an extension of X/4, so the change in extension will be:

Hence, the work done will become:

<u>W = 0.56 E</u>
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Learn more about Elastic Potential Energy here:
brainly.com/question/156316?referrer=searchResults
Attached picture shows Elastic Potential Energy.
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Answer: I believe the right answer would be C
I hope this helps. Correct me if im wrong