Tag: physics

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Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure
A fluid exert pressure 

  1. only downwards

  2. only upwards

  3. in all directions

  4. Fluids do not exert pressure
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

Pressure is exerted by fluids because of their weight. Static fluid pressure is exerted by the depth of the fluid, the density of the fluid and the acceleration of gravity. They exert pressure in all directions, which is given by $F=PA$
where $P$ is the pressure, and $A$ is the area on which force acts.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure
Which of the following can exert pressure

  1. Solids

  2. Liquids

  3. Gases

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

Pressure is exerted by fluids because of their weight. Static fluid pressure is exerted by the depth of the fluid, the density of the fluid and the acceleration of gravity.
Well knowingly, the solids exert pressure on the surface on which they are placed, given by $P=\dfrac{mg}{A}$
Hence correct answer is option D.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

Which of the following is true?

  1. Fluid do not have any weight

  2. Only liquids have weight

  3. Only gases have weight

  4. Fluids have weight
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

Pressure is exerted by fluids because of their weight. Static fluid pressure is exerted by the depth of the fluid, the density of the fluid and the acceleration of gravity.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

Two stretched membranes of area $2 cm^2$ and $3 cm^2$ are placed in a liquid at the same depth. The ratio of the pressure on them is :

  1. $1 : 1$

  2. $2 : 3$

  3. $3 : 2$

  4. $2^2 : 3^2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

pressure depends on depth not on area so the two stretched membrane would  have  equal pressure.

so ratio of their pressures would be 1 : 1.
hence option (A) is correct

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

Fill in the blank

Fluids at a given depth exert ______ pressure in all directions 

  1. same

  2. independent

  3. different

  4. zero
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fluids at a given depth exert same pressure in all directions.
Pressure of a liquid is directly proportional to the depth, and for a given depth the liquid exerts the same pressure in all directions according to Pascal's law.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

A block of wood floats separately in river water and then in ocean water. Then the weight of the displaced river water is

  1. equal to the weight of the displaced ocean water.

  2. less than the weight of the displaced ocean water.

  3. more than the weight of the displaced ocean water.

  4. not dependent on the density of the wooden block.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to the law of flotation, a floating object displaces a weight of fluid equal to its own weight. Since the weight of the wooden block is constant regardless of the fluid it floats in, the weight of the displaced fluid must be the same in both river water and ocean water.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

The fluids in a confined space exert pressure in which direction?

  1. Upward

  2. Downward

  3. Forward

  4. All directions
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same.

so option ( D) would be correct