(2) Number sense Object A is twice as dense as Object B, but both have identical

Question

(2) Number sense Object A is twice as dense as Object B, but both have identical volumes. Object C has the same density as Object A, but has twice the volume Assume that all three objects are completely submerged in water (because they are all denser than water and sink). Rank the buoyant force that these three object experience. Explain your ranking. a. The three objects are moved to a different, unknown fluid, which is known to be immiscible with water. A and C sink, but B floats. If you put this unknown fluid and water both into a beaker, which is on top? Why? b. (3) Iron wrecking ball goal: work with density What is the mass of a solid iron wrecking ball of radius 18 cm? The density of iron is 7800 kg/m3 a. b. If a ball of copper (=8900 kg/m 3) had the same mass as the iron ball, what would its radius be

Explanation / Answer

2a

Buoyant force is only dependent on volume of the object( is equal to the volume of liquid displaced )

Given,

Vc>Vb=Va ( comparison of volumes of object a,b and c)

So Buoyant force on c > Buoyant force on b = Buoyant force on a

2b

B sinks in water but floats in the fluid,

means B is more dense than water and less dense than fluid

so, fluid is more dense than water, which implies water floats on top of fluid as it is less dense than fluid.

3a

mass = density * volume

we need to find the volume,

given radius = 18cm = 0.18 m

volume of spherical ball = 4/3 pi (radius)^3

= 4/3 * pi * (0.18)^3

=0.0244 m^3

mass = density * volume

= 7800 * 0.0244

= 190.32 Kg

3b

Let radius of copper ball be r

mass of copper ball = 190.32kg

density = 8900 kg/m^3

190.32 = 8900 * volume

volume = 190.32 / 8900 = 0.0213 m^3

0.0213 = 4/3 pi r^3

r^3 = 0.005

r = 0.171 m = 17.1 cm

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

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