The figure at the right shows the full free-body diagram for two cubical blocks

Question

The figure at the right shows the full free-body diagram for two cubical blocks of identical volume that are held underneath the surface of a tank of water. The arrows represent the total force in each direction acting on the block. The labels on the arrows (U, D, L, and R) indicate the direction that the forces point (up, down, left, and right), not the side of the cube that is feeling the force. (The arrows on the faces at the front and back of the cube that point into and out of the page are not shown.)

3.1. When block #1 is released, it will sink. Rank the magnitudes of the forces FL, FR, FU, FD just after the block is released.

3.2. When block #2 is released, the block will float partially out of the water. Rank the magnitudes of the forces FL, FR, FU, FD just after the block is released

3.3. In which of the two cases is the buoyant force exerted by the water on the block greater?

(a) For block #1. (b) For block #2. (c) They are the same. (d) You do not have enough information to decide.

3.4. In which of the two cases is the force exerted by the water on the top of the block greater?

(a) For block #1. (b) For block #2. (c) They are the same. (d) You do not have enough information to decide.

Explanation / Answer

#.1)

bloock will sink when the gravitational force is more than the bouyant force.

so in this case

FL=FR and FD>FU

+++++++++++++++++++++++++++++++++++++++++++++

2)  when the object partially immersed in fluid its bouyant force is equal to weight of the liquid displaced

in this case

FL=FR and FD<FU

++++++++++++++++++++++++++++++++++++++++++++++++++++

in the case 2 i.e block 2 the bouyant force is greater than block

so the answer is

B) for block 2

+++++++++++++++++++++++++++++++++++++++++

3.4)

for block 1 the force on top is greater

so the answer is

a) for block 1

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.