fluids Flashcards
In a vacuum chamber on Earth, an object has no
a. mass.
b. heat.
c. temperature.
d. weight.
e. buoyant force.
e. buoyant force.
An empty jar is pushed open-side downward into water so that air trapped in it cannot get out. As the jar is pushed deeper, the buoyant force on the jar
a. decreases.
b. increases.
c. remains the same.
a. decreases.
Consider an air-filled balloon, weighted with a stone, that just barely floats in water. When the balloon is pushed beneath the surface, say about a meter deep, and then released, it will
a. stay where it is.
b. sink.
c. float back to the surface.
b. sink.
Which has the larger buoyant force, a balloon filled with helium or a balloon the same size filled with air?
a. the air balloon
b. the helium balloon
c. neither — they both experience the same buoyant force.
c. neither — they both experience the same buoyant force.
A balloon is buoyed up with a force equal to the
a. atmospheric pressure.
b. density of surrounding air.
c. weight of air it displaces.
d. weight of the balloon and contents.
e. all of these.
c. weight of air it displaces.
A 2 ton dirigible hovers in the air. The buoyant force acting on it is
a. zero.
b. less than 2 tons.
c. 2 tons.
d. more than 2 tons.
c. 2 tons.
If you are standing on the moon and release a balloon filled with helium gas, the balloon will
a. fall.
b. neither rise nor fall.
c. rise.
a. fall.
A woman holding her breath swims deeper and deeper beneath the water’s surface, her density
a. decreases
b. remains the same
c. increases
c. increases
The reason water can be pumped out of a well using an old-fashioned farm-type pump is that the
a. pump sucks the water up from the well
b. water level is very close to the pump
c. pump scoops up the water and lifts it to the top
d. water is pushed to the surface by the atmosphere
e. any of these (depends on the type of pump)
d. water is pushed to the surface by the atmosphere
A swimmer cannot have a snorkel tube that is more than a meter deep. The reason for this is that at that depth the lungs are so compressed
a. they will be buoyed up leaving the swimmer breathless
b. air in the lungs cannot easily be expelled
c. air tends to liquefy in the snorkel tube
d. low-pressure air at the surface is difficult to inhale
e. all of these
d. low-pressure air at the surface is difficult to inhale
- As a whale swims deeper into the ocean, increasing water pressure squeezes its volume, making it smaller. As the whale swims deeper and deeper, the buoyant force on it
a. increases
b. remains unchanged
c. decreases
c. decreases
- Which has the larger buoyant force, a balloon filled with helium or a balloon the same size filled with air?
a. The air balloon
b. The helium balloon
c. Neither they are equal
c. Neither they are equal
- Which has more weight, a balloon filled with helium or a balloon the same size filled with air?
a. The air balloon
b. The helium balloon
c. Neither they are equal
a. The air balloon
- A balloon is buoyed up with a force equal to the
a. atmospheric pressure
b. density of surrounding air
c. weight of air it displaces
d. weight of the balloon and contents
c. weight of air it displaces
- A bubble of air released from the bottom of a lake?
a. becomes larger as it rises
b. becomes smaller as it rises
c. rises to the top at constant volume
d. alternately expands and contracts as it rises
a. becomes larger as it rises
