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Flashcards in Test 4 Deck (10)
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1
Q

What is pressure?

A

Pressure is a force divided by the area over which the force is divided
Pressure = Force / area

2
Q

What does liquid pressure depend on?

A

Your depth and the density of the liquid.

Liquid Pressure = weight density * depth

3
Q

What is buoyancy? What causes it?

A

The apparent loss of weight experienced by objects submerged in a liquid. When an object is submerged, water exerts an upward force that is exactly opposite to the direction of gravity’s pull, called the buoyant force. This occurs because of the greater pressure at the bottom of an object as opposed to the top of it, since liquid pressure depends on depth.

4
Q

What is Archimedes Principle? How can you express it numerically?

A

An immersed object is buoyed up by a force equal to the weight of the fluid it displaces. The difference between the upward-acting and the downward acting forces due to the similar pressure differences on a submerged cube is numerically identical to the weight of the fluid displaced.
Fluid displaced = |buoyant force - downward acting force|

5
Q

What is the buoyant force equal to?

A

The weight of the volume of fluid displaced.

6
Q

What makes an object sink or float?

A

An object more dense than the fluid will sink.
An object less dense than the fluid will float.
An object of equal density to the fluid will neither sink nor float.

7
Q

How do you determine an objects density?

A

Weight/volume

8
Q

What is the principle of flotation?

A

A floating object displaces a weight of fluid equal to its own weight.

9
Q

What is Pascal’s Principle?

A

A change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid.

10
Q

How can one end of a piston with 10kg of weight on it, keep balance with the other end that has 500kg of weight on it?

A

This happens because of the u-shape of the piston. The end of the piston with the 500kg of weight must be 50 times the size of the end with 10kg of weight on it, however when the 10kg mass pushes down on the liquid in the piston the pressure must be applied to all the water in the enclosed piston, due to Pascal’s principle, allowing the 10kg mass to stay level with the 500kg mass.