Question 1

In the first image, a force $$F is $$applied at an angle $$\alpha to $$the normal of a surface $$S. $$What is the correct formula for the pressure exerted by the force on the surface?

Accepted Answer

$$P = \frac{F \cos \alpha}{S}$$

Question 2

Refer to the second image. A block of mass $$m is $$resting on an inclined plane at angle $$\alpha. $$What is the pressure exerted by the block on the plane if the contact area is $$S$$?

Accepted Answer

$$P = \frac{mg \cos \alpha}{S}$$

Question 3

In the third image, a force $$F is $$applied to a nail with two different ends: $$S_1 ($$large area) and $$S_2 ($$small area). If $$S_1$$ \gg $$S_2$$, which end exerts greater pressure and why?

Accepted Answer

The end with $$S_2$$ because pressure is inversely proportional to area.

Question 4

The fourth image shows a person cutting bread with a knife. Why is a sharp knife more effective than a blunt one?

Accepted Answer

A sharp knife has a smaller area, increasing pressure.

Question 5

In the fifth image, three different arrangements of identical cubes are shown. Which arrangement exerts the greatest pressure on the surface and why?

Accepted Answer

The arrangement with the smallest contact area, because pressure is inversely proportional to area.

Question 6

In the sixth image, a liquid of density $$d$$ and height $$h is in a $$container with base area $$S. $$What is the pressure at the bottom of the container?

Accepted Answer

$$P = h d g$$

Question 7

In the seventh image, two containers have different liquids and heights. If $$P_1$$ and $$P_2$$ are the pressures at the bottom, which equation is correct?

Accepted Answer

$$\frac{P_1$}{P_2$} = \frac{2 d_1$}{3 d_2$}$$

Question 8

The eighth image shows two objects of different shapes submerged in a liquid. What can be said about the pressure exerted by the liquid on the surfaces of these objects at the same depth?

Accepted Answer

The pressure is the same at the same depth, regardless of shape.

Question 9

In the ninth image, several connected vessels of different shapes contain the same liquid. What is true about the liquid levels in each vessel?

Accepted Answer

The liquid levels are the same because the pressure at the bottom must be equal.

Question 10

In the tenth image, three pressure forces $$F_1$$, $$F_2$$, and $$F_3$$ act on different surfaces of a container filled with liquid. If the average depth for each surface is considered, which force is the greatest?

Accepted Answer

$$F_3$$ because it is at the greatest average depth and has the largest area.

Question 11

The eleventh image shows how liquid pressure and pressure force change over time as water is added to a container. What is the relationship between the two graphs?

Accepted Answer

Both increase linearly with time as the height of the liquid increases.

Question 12

In the twelfth image, two immiscible liquids with densities $$d_1$$ and $$d_2$$ and heights $$h_1$$ and $$h_2$$ are stacked. What is the total pressure at the bottom?

Accepted Answer

$$P = h_1$ d_1$ g + h_2$ d_2$ g$$

Question 13

In the thirteenth image, a cylinder of weight $$G$$ and density $$d is $$placed on a surface of area $$S. $$What is the pressure exerted on the surface?

Accepted Answer

$$P = \frac{G}{S}$$

Question 14

The fourteenth image shows three containers with different shapes but the same base area $$S$$ and liquid height. Which container exerts the greatest pressure force on the base?

Accepted Answer

All containers exert the same pressure force if the liquid height and base area are the same.

Question 15

In the fifteenth image, two horizontal surfaces $$S_1$$ and $$S_2$$ are at different depths in two different liquids with densities $$d_1$$ and $$d_2. If$$ $$h_1$$ and $$h_2$$ are the heights of the liquids above each surface, what is the ratio of the pressure forces $$F_1$$/$$F_2$$?

Accepted Answer

$$\frac{F_1$}{F_2$} = \frac{d_1$ h_1$ S_1$}{d_2$ h_2$ S_2$}$$

Question 16

The sixteenth image shows a liquid escaping from a hole at height $$h$$ above the ground. What determines the horizontal distance $$X$$ the liquid travels before hitting the ground?

Accepted Answer

The height $$h$$ and the initial velocity of the liquid.

Question 17

In the seventeenth image, two diagrams show a liquid being compressed. What property of liquids is being demonstrated?

Accepted Answer

Liquids are not compressible.

Question 18

The eighteenth image shows a U-tube with two pistons applying forces $$F_1$$ and $$F_2 on a $$liquid. According to Pascal's Principle, what is true about the pressures $$P_1$$ and $$P_2 at $$the two ends?

Accepted Answer

$$P_1$$ = $$P_2 if $$the heights are the same.

Fluid Pressure: Solids, Liquids, and Gases – Concepts and Applications

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