Sep 28, 2018 The buoyant force is an upward force that opposes the downward force of gravity. The magnitude of the buoyant force determines whether an object will sink, float, or rise when submerged in a fluid. An object will sink if the gravitational force acting on it is greater than the buoyant force. A the buoyant force of fluid i is greater than the buoyant forces of the other two fluids B the buoyant force of fluid 3 is greater than the buoyant forces of the other two fluids C the three fluids exert the same buoyant force D the object displace the same volume of all three fluids E none of these are true 13. Two life preservers have identical volumes, but one is filled with styrofoam while the other is filled with sand. When the two life preservers are fully submerged, the buoyant force is. The buoyant force can be different here, if the material's density is greater than water's, and the objects are shaped such that one sinks while the other one floats on the surface.

Multiple Choice Questions

1) Water pressure is greatest against the

a. the top of a submerged object.
b. bottom of a submerged object.
c. sides of a submerged object.
d. is the same against all surfaces.

Reasoning: The bottom of the object is at a higher depth. Since pressure depends on depth, the bottom is going to be acted by a higher pressure. See page 247.

2) A dam is thicker at the bottom than at the top partly because

a. water is denser at deeper levels.
b. water pressure is greater with increasing depth.
c. surface tension exists only on the surface of liquids.
d. it looks better.

3) The pressure in a liquid depends on liquid Free windows 10 themes deviantart.

a. density.
b. depth.
c. both of these.
d. neither of these.

4) The pressure at the bottom of a jug filled with water does NOT depend on

a. the acceleration due to gravity.
b. water density.
c. the height of the liquid.
d. surface area of the water.

5) One liter of water has a mass of

a. 1 kilogram.
b. 1 newton.
c. both of these.
d. neither of these.

Reasoning: One liter means 1000 cm3 of water. Density of water is 1 g/cm3. Thus 1000 cm3 of waer has a mass of: (1000 cm3)x(1 g/cm3) = 1000 g = 1 kg.

6) The mass of a cubic meter of water is

a. 1 kg.
b. 10 kg.
c. 100 kg.
d. 1000 kg.

7) Pumice is a volcanic rock that floats. Its density is

a. less than the density of water.
b. equal to the density of water.
c. more than the density of water.

Reasoning: To float, the density of the object must be less than the density of the fluid.

8) The reason that buoyant force acts upward on a submerged object is that

a. it acts in a direction to oppose gravity.
b. if it acted downward, nothing would float.
c. the weight of fluid displaced reacts with an upward force.
d. upward pressure against the bottom is greater than downward pressure against the top of the submerged object.

Reasoning: This issue is discussed in the computer lesson on buoyancy.

9) A completely submerged object always displaces its own

a. volume of fluid.
b. weight of fluid.
c. density of fluid.
d. all of these.

10) A fish normally displaces its own

a. volume of water.
b. weight of water.
c. both of these.
d. neither of these.

Reasoning: See page 254 for more details. Fish have a density close to the density of water. Thus the displaced volume of water has the same weight as the fish.

11) When a boat sails from fresh water to salt water, the boat will float

a. lower in the water.
b. higher in the water.
c. at the same water level.

Reasoning: In salt water, the density of water is higher. Thus less volume of water is needed to produce the same buoyant force.See page 255.

12) What is the buoyant force acting on a 10-ton ship floating in the ocean?

a. less than 10 tons
b. 10 tons
c. more than 10 tons
d. depends on density of sea water

13) What is the weight of water displaced by a 100-ton floating ship?

a. less than 100 tons
b. 100 tons
c. more than 100 tons
d. 100 cubic meters

14) When an object is partly or wholly immersed in a liquid, it is buoyed up

a. by a force equal to its own weight.
b. by a force equal to the weight of liquid displaced.
c. and floats because of Archimedes principle.
d. but nevertheless sinks.

15) The buoyant force on an object is least when the object is

a. partly submerged.
b. submerged near the surface.
c. submerged near the bottom.
d. none of these.

16) The buoyant force on a rock is least when the rock is submerged

a. near the surface.
b. halfway to the bottom.
c. near the bottom.
d. all of the above.
e. none of the above

Reasoning: The buoyant force will remain the same as long as the object is totally submerged. This is because the buoyant force is the weight of the displaced water. As the object sinks deeper, the displaced water remains the same and so is the buoyant force.

17) The reason a life jacket helps you float is

a. the jacket makes you weigh less.
b. the jacket has the same density as an average human.
c. the jacket repels water.
d. if you sink, the jacket sinks.
e. the density of both you and the jacket together is less than your density alone.

18) Blood pressure is normally greater in your

a. ears.
b. feet.
c. same in each.

19) Three holes are drilled in a water tower, which is filled with water, at the positions shown. Water will spurt the greatest horizontal distance from hole

Buoyant Force Is Greatest On A Submerged Area

a. A.
b. B.
c. C.
d. The horizontal distance will be the same for all three holes.

20) Lobsters live on the bottom of the ocean. The density of a lobster is

a. greater than the density of sea water.
b. equal to the density of sea water.
c. less than the density of sea water.

21) A lobster crawls onto a bathroom scale submerged at the bottom of the ocean. Compared to its weight above the surface, the lobster will have an apparent weight under water that is

a. greater.
b. less.
c. the same.

22) Two life preservers have identical volumes, but one is filled with styrofoam while the other is filled with sand. When the two life preservers are fully submerged, the buoyant force is greater on the one filled with

Buoyant force is greatest on a submerged

a. styrofoam.
b. sand.
c. same on each as long as their volumes are the same.

23) When an ice cube in a glass of water melts, the water level

a. rises.
b. falls.
c. remains the same.

Buoyant Force Is Greatest On A Submerged Space

24) A rock suspended by a weighing scale weighs 5 N out of water and 3 N when submerged in water. What is the buoyant force on the rock?

How Do You Find The Buoyant Force Of A Submerged Object

a. 8 N
b. 5 N
c. 3 N
d. 2 N

25) An egg is placed at the bottom of a bowl filled with water. Salt is slowly added to the water until the egg rises and floats. From this experiment, one concludes

a. calcium in the egg shell is repelled by sodium chloride.
b. the density of salt water exceeds the density of egg.
c. buoyant force does not always act upward.
d. salt sinks to the bottom.

Multiple Choice Questions

Buoyant Force Is Greatest On A Submerged Area

Buoyant Force Is Greatest On A Submerged Space

How Do You Find The Buoyant Force Of A Submerged Object

Buoyant Force Is Greatest On A Submerged Wave