Buzz
Solving Exercise C1 on page 36 Physics 8 Textbook
Exercise:
Suspending a heavy object on a force meter, the force meter reads value P (H.10.2a). Submerging the heavy object in water, the force meter reads value P1 (H.10.2b). If P1 is smaller than P, what does it indicate?
Solution:
P1 being smaller than P indicates that the fluid has exerted an upward buoyant force on the object.
Solving Exercise C2 on page 36 Physics 8 Textbook
Exercise:
Choose the appropriate word to fill in the blank in the following conclusion:
Conclusion: An object submerged in a fluid experiences a buoyant force directed from ________.
Solution:
An object submerged in a liquid experiences an upward-directed buoyant force along the vertical direction.
Solving Exercise C3 on page 37 of Physics 8 textbook
Exercise:
Prove that the experiment in Figure 10.3 demonstrates the accuracy of the prediction about the magnitude of the action-reaction force mentioned above.
Explaining Exercise C4 on page 38 of Physics 8 textbook
Stating the problem:
Provide an explanation for the phenomenon mentioned at the beginning of the exercise.
'When pulling water up from the well, we notice that the bucket is lighter when submerged under water than when lifted above the water surface (H.10.1). Why is that?'
Solution:
Pulling the bucket when submerged in water feels lighter than when pulled in the air because the bucket immersed in water experiences an upward buoyant force, which is equal to the weight of the water displaced by the bucket.
Solving Exercise C5 on page 38 of Physics 8 textbook
Stating the problem:
Which experiences a greater buoyant force: an aluminum block or a steel block, both submerged in water?
Solution:
The buoyant force depends on the density of water and the volume of water displaced by each block. Since both blocks have the same volume, they experience the same magnitude of buoyant force.
Solving Exercise C6 on page 38 of Physics 8 textbook
Stating the problem:
Two copper blocks with equal volumes, one submerged in water and the other in oil. Which experiences a greater buoyant force?
Solution:
The buoyant force acting on the copper block submerged in water: FAn = dn.V
Buoyant force acting on the copper block submerged in oil: FAd = dd.V
Since the density of water is greater than the density of oil: dn > dd => FAn > FAd.
Solving Exercise C7 on page 38 of Physics 8 textbook
Stating the problem:
To experimentally test the prediction regarding the magnitude of the Archimedes' thrust, we propose using a balance scale instead of a force gauge as illustrated in figure 10.4.
Solution:
We can verify the prediction about the magnitude of Archimedes' thrust using a balance scale setup as follows:
- Step 1: Hang a small waterproof object on a cup placed on the scale's platform.
The mass of the object and the cup (left dish) equals precisely the weight of the weights (right dish).
- Step 2: The object remains suspended on the balance but is fully immersed in an overflow vessel B filled with water, causing some water to flow out into cup C and the balance to tilt towards the weights.
- Step 3: Keeping the object in the overflow vessel while simultaneously pouring water from cup C into cup A on the balance until balance is restored.
Thus, the Archimedes' thrust equals the weight of the displaced water.
Pressure is the next topic in Chapter I of Physics 8, along with referring to Exercise solutions on pages 25, 26, 27 of Physics 8 to grasp the concepts and study Physics 8 effectively.
In Chapter I of Mechanics, students learn about Frictional Forces. Refer to Exercise solutions on pages 21, 22, 23 of Physics 8 to study Physics 12 effectively.
