Question 1

Which of the following best defines pressure in the context of fluids?

Accepted Answer

Pressure is the ratio of force to the area over which the force is applied.

Question 2

A 60 kg pirate stands on her peg leg, which has an area of $$0.002\ m^2$. What is the pressure exerted on the ground by the peg leg? (Take g = 9.8$$\ $$m/s^2)$$

Accepted Answer

$$2.94 	imes 10^5$\ Pa$$

Question 3

Which unit is most commonly used in scientific contexts to measure pressure?

Accepted Answer

Pascal ($$Pa)$$

Question 4

If a mosquito exerts a force of $$1.8 	imes 10$$^{-5}$$\ N on $$your skin with its sharp proboscis, and the contact area is $$1.0 	imes 10$$^{-8}$$\ m^2$, what is the pressure exerted?

Accepted Answer

$$1.8 	imes 10^6$\ Pa$$

Question 5

Why does a hammer with a sharp point break a window more easily than a standard hammer?

Accepted Answer

The sharp point concentrates the force over a smaller area, increasing the pressure.

Question 6

A person drops a $$0.5\ kg$$ bag of flour and a $$0.5\ kg$$ block of metal on their toes. Both have the same mass. Why does the metal hurt more?

Accepted Answer

The metal block has a smaller contact area, resulting in higher pressure.

Question 7

What is the formula for pressure ($$P) in $$terms of force ($$F) $$and area ($$A$$)?

Accepted Answer

$$P = \frac{F}{A}$$

Question 8

At sea level, the atmospheric pressure is approximately $$101,300\ Pa. $$What is this value in atmospheres ($$atm$$)? (1 $$atm$$ = $$101,300\ Pa)$$

Accepted Answer

$$1\ atm$$

Question 9

Which statement about fluid pressure is correct?

Accepted Answer

Fluid pressure at a given depth acts equally in all directions.

Question 10

A swimmer feels more pressure on their eardrums as they dive deeper underwater. What is the primary reason for this?

Accepted Answer

The weight of the water above increases with depth.

Question 11

A canvas sheet is shot with an arrow and another identical sheet is hit by a truck at the same speed. Which sheet will be more deformed at the point of impact and why?

Accepted Answer

The sheet hit by the arrow, because the force is concentrated over a smaller area, increasing pressure.

Question 12

If the area of contact is reduced by a factor of 10, but the force remains constant, what happens to the pressure?

Accepted Answer

Pressure increases by a factor of 10.

Question 13

Which of the following is NOT a correct statement about atmospheric pressure?

Accepted Answer

Atmospheric pressure increases with altitude.

Question 14

A plug is removed from a container of water at three different depths. Which spurt of liquid will travel the furthest from the container?

Accepted Answer

The spurt from the lowest hole, because pressure increases with depth.

Question 15

A suction cup sticks to a wall by removing air from between the cup and the wall. What is the main physical principle that allows it to stick?

Accepted Answer

Atmospheric pressure outside the cup pushes it against the wall.

Question 16

Which of the following scenarios would result in the highest pressure?

Accepted Answer

A 50 kg person standing on one heel with an area of $$0.01\ m^2$

Question 17

If the pressure exerted by a fluid at rest always acts at right angles to any surface, what is the direction of the force on the walls of a container?

Accepted Answer

Perpendicular to the surface of the wall.

Question 18

A block exerts a force of $$200\ N on $$the ground. If the area of contact is $$0.05\ m^2$, what is the pressure?

Accepted Answer

$$4,000\ Pa$$

Question 19

Which of the following is a common misconception about pressure?

Accepted Answer

Pressure is the same as density.

Pressure in Fluids: Concepts, Calculations, and Applications

Guida di studio - Domande di pratica

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