Question

Straws work on the principle of the outside atmospheric pressure pushing the fluid (for example water) up the straw after you have lowered the pressure at the top of the straw (in your mouth). Assuming you could create a perfect vacuum in your mouth, what is the longest vertical straw you could drink water from?

1.65 m

4.28 m

7.71 m

10.3 m

8)  How would this answer change if you were on a planet with a much lower atmospheric pressure?

increases

decreases

remains the same

9)  A block of wood (density 550 kg/m³) and a block of metal (density 2700 kg/m³) with equal volume are placed 1 m under water in a swimming pool. Which has a greater buoyant force on it?

the metal

the wood

they have the same buoyant force

10)  Which has a greater force of gravity on it?

the metal

the wood

they have the same force of gravity

11)  Compare the buoyant force to the force of gravity for each object.

In both cases the buoyant force is greater.

In both cases the force of gravity is greater.

For the metal, the buoyant force is greater; for the wood, the force of gravity is greater.

For the wood, the buoyant force is greater; for the metal, the force of gravity is greater.

12)  If they were taken to a depth of 10 m what would happen to the buoyant force on each (assume the density of water is constant and the objects are incompressible)?

they increase

they decrease

they remain the same

13)  If the objects were connected together, would they sink or float?

they would sink

they would float

they would stay right where the are!

14)  Water is flowing through a pipe that slowly gets smaller as it rises to the bathroom on your second floor (10 m high). The pipe coming into your house is 3 cm in diameter, the pressure there is 3x10⁵ Pa, and the water is moving at .8 m/s. The diameter of the pipe in the upstairs bathroom is 1.5 cm. How fast is the water moving right before it leaves the pipe in the bathroom?

.2 m/s

.4 m/s

1.6 m/s

3.2 m/s

15)  What is the pressure of the water in the pipe right before it leaves the pipe?

1.50x10⁵ Pa

1.97x10⁵ Pa

2.88x10⁵ Pa

3.67x10⁵ Pa

Answer 1

Straws work on the principle of the outside atmospheric pressure pushing the fluid (for example water) up the straw after you have lowered the pressure at the top of the straw (in your mouth). Assuming you could create a perfect vacuum in your mouth, what is the longest vertical straw you could drink water from?

1.65 m

4.28 m

7.71 m

10.3 m

8)  How would this answer change if you were on a planet with a much lower atmospheric pressure?

increases

decreases

remains the same

9)  A block of wood (density 550 kg/m³) and a block of metal (density 2700 kg/m³) with equal volume are placed 1 m under water in a swimming pool. Which has a greater buoyant force on it?

the metal

the wood

they have the same buoyant force

10)  Which has a greater force of gravity on it?

the metal

the wood

they have the same force of gravity

11)  Compare the buoyant force to the force of gravity for each object.

In both cases the buoyant force is greater.

In both cases the force of gravity is greater.

For the metal, the buoyant force is greater; for the wood, the force of gravity is greater.

For the wood, the buoyant force is greater; for the metal, the force of gravity is greater.

12)  If they were taken to a depth of 10 m what would happen to the buoyant force on each (assume the density of water is constant and the objects are incompressible)?

they increase

they decrease

they remain the same

13)  If the objects were connected together, would they sink or float?

they would sink

they would float

they would stay right where the are!

14)  Water is flowing through a pipe that slowly gets smaller as it rises to the bathroom on your second floor (10 m high). The pipe coming into your house is 3 cm in diameter, the pressure there is 3x10⁵ Pa, and the water is moving at .8 m/s. The diameter of the pipe in the upstairs bathroom is 1.5 cm. How fast is the water moving right before it leaves the pipe in the bathroom?

.2 m/s

.4 m/s

1.6 m/s

3.2 m/s

15)  What is the pressure of the water in the pipe right before it leaves the pipe?

1.50x10⁵ Pa

1.97x10⁵ Pa

2.88x10⁵ Pa

3.67x10⁵ Pa