Answer:
B. The object's volume
Explanation:
When an object is immersed in a fluid, it experiences an upward force which is called buoyant force. The magnitude of the buoyant force is given by:

where
is the density of the fluid in which the object is immersed
is the volume of the fluid displaced by the object
is the acceleration due to gravity
When the object is totally immersed in the fluid,
corresponds to the volume of the object; when the object is only partially immersed,
corresponds only to the volume of the part of the object immersed.
From the formula, we see that the greatest buoyant force is experienced by the object when it is fully immersed. Moreover, we see that the buoyant force depends only on one property of the object: its volume. Therefore, the correct choice is
B. The object's volume
Answer:
20 J
Explanation:
Given:
Weight of the book is, 
Height or displacement of the book is, 
The work done on the book to raise it to a height of 2 m on a shelf is against gravity. The gravitational force acting on the book is equal to its weight. Now, in order to raise it, an equal amount of force must be applied in the opposite direction.
So, the force applied by me should be equal to weight of the body and in the upward direction. The displacement is also in the upward direction.
Now, work done by the applied force is equal to the product of force applied and displacement of book in the direction of the applied force.
Therefore, work done is given as:

Therefore, the work done to raise a book to a height 2 m from the floor is 20 J.
Newton's second law tells you:
Sum of forces on an object = ma
Here, the forces acting on the bundle are the tension in the string and the force of gravity, these two must combine to yield the acceleration of the bundle.
So we have:
T-mg = ma
or T=m(g+a)
We know m=8.7kg, we need to find a from the information
starting from rest, an accelerating object covers distance according to:
<span>dist = 1/2 at^2 </span>
to cover 1m in 1.8s, we have:
a=2d/t^2 = 2x1/1.8^2 = 0.62 m/s/s
Thus, the tension in the string is:
<span>T = m(g+a)
= 8.7</span>kg(9.8m/s/s+0.62m/s/s)
<span>
<span>T = 90.654 N
</span>
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
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