04. Pascal's Law and Pressure Inside the Fluid
Mechanical Properties of Fluids

143172 The air pressure at sea level is $101325 \mathrm{~Pa}$. At the centre of a rarefaction of a sound wave in air, the pressure is $91000 \mathrm{~Pa}$. Which is the most likely pressure at the centre of a compression of the same wave?

1 $91000 \mathrm{~Pa}$
2 $101000 \mathrm{~Pa}$
3 $111600 \mathrm{~Pa}$
4 $121000 \mathrm{~Pa}$
Mechanical Properties of Fluids

143173 The volumes of containers $A$ and $B$, connected by a tube and a closed valve, are $V$ and $4 V$ respectively. Both the containers $A$ and $B$ have the same ideal gas at pressures (temperatures) $5.0 \times 10^{5} \mathrm{~Pa}(300 \mathrm{~K})$ and $1.0 \times 10^{5} \mathrm{~Pa}(400 \mathrm{~K})$, respectively. The valve is opened to allow the pressure to equalize, but the temperature of each container is kept constant at its initial value. Find the common pressure in the containers

1 $2.5 \times 10^{5} \mathrm{~Pa}$
2 $2.0 \times 10^{5} \mathrm{~Pa}$
3 $3.0 \times 10^{5} \mathrm{~Pa}$
4 $1.5 \times 10^{5} \mathrm{~Pa}$
Mechanical Properties of Fluids

143174 The cylindrical tube of a spray pump has radius $R$, one end of which has $n$ fine holes, each of radius $r$. If the speed of the liquid in the tube is $v$, the speed of the ejection of the liquid through the holes is

1 $\frac{v R^{2}}{n^{2} r^{2}}$
2 \(\frac{\mathrm{vR}^2}{\mathrm{nr}^2}\)
3 $\frac{\mathrm{vR}}{\mathrm{n}^{3} \mathrm{r}^{2}}$
4 $\frac{\mathrm{v}^{2} \mathrm{R}}{\mathrm{nr}}$
Mechanical Properties of Fluids

143175 The pressure on the top surface of an aeroplane wing is $0.8 \times 10^{5} \mathrm{~Pa}$ and the pressure on the bottom surface is $0.75 \times 10^{5} \mathrm{~Pa}$. If the area of each surface is $50 \mathrm{~m}^{2}$, the dynamic lift on the wing is

1 $25 \times 10^{4} \mathrm{~N}$
2 $0.5 \times 10^{4} \mathrm{~N}$
3 $5 \times 10^{4} \mathrm{~N}$
4 $0.25 \times 10^{5} \mathrm{~N}$
Mechanical Properties of Fluids

143176 An aeroplane of mass $3 \times 10^{4} \mathrm{~kg}$ and total wing area of $120 \mathrm{~m}^{2}$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in $\mathrm{kPa}$ is $(\mathrm{g}=10$ $\mathbf{m} / \mathbf{s}^{2}$ )

1 2.5
2 5.0
3 10.0
4 12.5
Mechanical Properties of Fluids

143172 The air pressure at sea level is $101325 \mathrm{~Pa}$. At the centre of a rarefaction of a sound wave in air, the pressure is $91000 \mathrm{~Pa}$. Which is the most likely pressure at the centre of a compression of the same wave?

1 $91000 \mathrm{~Pa}$
2 $101000 \mathrm{~Pa}$
3 $111600 \mathrm{~Pa}$
4 $121000 \mathrm{~Pa}$
Mechanical Properties of Fluids

143173 The volumes of containers $A$ and $B$, connected by a tube and a closed valve, are $V$ and $4 V$ respectively. Both the containers $A$ and $B$ have the same ideal gas at pressures (temperatures) $5.0 \times 10^{5} \mathrm{~Pa}(300 \mathrm{~K})$ and $1.0 \times 10^{5} \mathrm{~Pa}(400 \mathrm{~K})$, respectively. The valve is opened to allow the pressure to equalize, but the temperature of each container is kept constant at its initial value. Find the common pressure in the containers

1 $2.5 \times 10^{5} \mathrm{~Pa}$
2 $2.0 \times 10^{5} \mathrm{~Pa}$
3 $3.0 \times 10^{5} \mathrm{~Pa}$
4 $1.5 \times 10^{5} \mathrm{~Pa}$
Mechanical Properties of Fluids

143174 The cylindrical tube of a spray pump has radius $R$, one end of which has $n$ fine holes, each of radius $r$. If the speed of the liquid in the tube is $v$, the speed of the ejection of the liquid through the holes is

1 $\frac{v R^{2}}{n^{2} r^{2}}$
2 \(\frac{\mathrm{vR}^2}{\mathrm{nr}^2}\)
3 $\frac{\mathrm{vR}}{\mathrm{n}^{3} \mathrm{r}^{2}}$
4 $\frac{\mathrm{v}^{2} \mathrm{R}}{\mathrm{nr}}$
Mechanical Properties of Fluids

143175 The pressure on the top surface of an aeroplane wing is $0.8 \times 10^{5} \mathrm{~Pa}$ and the pressure on the bottom surface is $0.75 \times 10^{5} \mathrm{~Pa}$. If the area of each surface is $50 \mathrm{~m}^{2}$, the dynamic lift on the wing is

1 $25 \times 10^{4} \mathrm{~N}$
2 $0.5 \times 10^{4} \mathrm{~N}$
3 $5 \times 10^{4} \mathrm{~N}$
4 $0.25 \times 10^{5} \mathrm{~N}$
Mechanical Properties of Fluids

143176 An aeroplane of mass $3 \times 10^{4} \mathrm{~kg}$ and total wing area of $120 \mathrm{~m}^{2}$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in $\mathrm{kPa}$ is $(\mathrm{g}=10$ $\mathbf{m} / \mathbf{s}^{2}$ )

1 2.5
2 5.0
3 10.0
4 12.5
Mechanical Properties of Fluids

143172 The air pressure at sea level is $101325 \mathrm{~Pa}$. At the centre of a rarefaction of a sound wave in air, the pressure is $91000 \mathrm{~Pa}$. Which is the most likely pressure at the centre of a compression of the same wave?

1 $91000 \mathrm{~Pa}$
2 $101000 \mathrm{~Pa}$
3 $111600 \mathrm{~Pa}$
4 $121000 \mathrm{~Pa}$
Mechanical Properties of Fluids

143173 The volumes of containers $A$ and $B$, connected by a tube and a closed valve, are $V$ and $4 V$ respectively. Both the containers $A$ and $B$ have the same ideal gas at pressures (temperatures) $5.0 \times 10^{5} \mathrm{~Pa}(300 \mathrm{~K})$ and $1.0 \times 10^{5} \mathrm{~Pa}(400 \mathrm{~K})$, respectively. The valve is opened to allow the pressure to equalize, but the temperature of each container is kept constant at its initial value. Find the common pressure in the containers

1 $2.5 \times 10^{5} \mathrm{~Pa}$
2 $2.0 \times 10^{5} \mathrm{~Pa}$
3 $3.0 \times 10^{5} \mathrm{~Pa}$
4 $1.5 \times 10^{5} \mathrm{~Pa}$
Mechanical Properties of Fluids

143174 The cylindrical tube of a spray pump has radius $R$, one end of which has $n$ fine holes, each of radius $r$. If the speed of the liquid in the tube is $v$, the speed of the ejection of the liquid through the holes is

1 $\frac{v R^{2}}{n^{2} r^{2}}$
2 \(\frac{\mathrm{vR}^2}{\mathrm{nr}^2}\)
3 $\frac{\mathrm{vR}}{\mathrm{n}^{3} \mathrm{r}^{2}}$
4 $\frac{\mathrm{v}^{2} \mathrm{R}}{\mathrm{nr}}$
Mechanical Properties of Fluids

143175 The pressure on the top surface of an aeroplane wing is $0.8 \times 10^{5} \mathrm{~Pa}$ and the pressure on the bottom surface is $0.75 \times 10^{5} \mathrm{~Pa}$. If the area of each surface is $50 \mathrm{~m}^{2}$, the dynamic lift on the wing is

1 $25 \times 10^{4} \mathrm{~N}$
2 $0.5 \times 10^{4} \mathrm{~N}$
3 $5 \times 10^{4} \mathrm{~N}$
4 $0.25 \times 10^{5} \mathrm{~N}$
Mechanical Properties of Fluids

143176 An aeroplane of mass $3 \times 10^{4} \mathrm{~kg}$ and total wing area of $120 \mathrm{~m}^{2}$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in $\mathrm{kPa}$ is $(\mathrm{g}=10$ $\mathbf{m} / \mathbf{s}^{2}$ )

1 2.5
2 5.0
3 10.0
4 12.5
Mechanical Properties of Fluids

143172 The air pressure at sea level is $101325 \mathrm{~Pa}$. At the centre of a rarefaction of a sound wave in air, the pressure is $91000 \mathrm{~Pa}$. Which is the most likely pressure at the centre of a compression of the same wave?

1 $91000 \mathrm{~Pa}$
2 $101000 \mathrm{~Pa}$
3 $111600 \mathrm{~Pa}$
4 $121000 \mathrm{~Pa}$
Mechanical Properties of Fluids

143173 The volumes of containers $A$ and $B$, connected by a tube and a closed valve, are $V$ and $4 V$ respectively. Both the containers $A$ and $B$ have the same ideal gas at pressures (temperatures) $5.0 \times 10^{5} \mathrm{~Pa}(300 \mathrm{~K})$ and $1.0 \times 10^{5} \mathrm{~Pa}(400 \mathrm{~K})$, respectively. The valve is opened to allow the pressure to equalize, but the temperature of each container is kept constant at its initial value. Find the common pressure in the containers

1 $2.5 \times 10^{5} \mathrm{~Pa}$
2 $2.0 \times 10^{5} \mathrm{~Pa}$
3 $3.0 \times 10^{5} \mathrm{~Pa}$
4 $1.5 \times 10^{5} \mathrm{~Pa}$
Mechanical Properties of Fluids

143174 The cylindrical tube of a spray pump has radius $R$, one end of which has $n$ fine holes, each of radius $r$. If the speed of the liquid in the tube is $v$, the speed of the ejection of the liquid through the holes is

1 $\frac{v R^{2}}{n^{2} r^{2}}$
2 \(\frac{\mathrm{vR}^2}{\mathrm{nr}^2}\)
3 $\frac{\mathrm{vR}}{\mathrm{n}^{3} \mathrm{r}^{2}}$
4 $\frac{\mathrm{v}^{2} \mathrm{R}}{\mathrm{nr}}$
Mechanical Properties of Fluids

143175 The pressure on the top surface of an aeroplane wing is $0.8 \times 10^{5} \mathrm{~Pa}$ and the pressure on the bottom surface is $0.75 \times 10^{5} \mathrm{~Pa}$. If the area of each surface is $50 \mathrm{~m}^{2}$, the dynamic lift on the wing is

1 $25 \times 10^{4} \mathrm{~N}$
2 $0.5 \times 10^{4} \mathrm{~N}$
3 $5 \times 10^{4} \mathrm{~N}$
4 $0.25 \times 10^{5} \mathrm{~N}$
Mechanical Properties of Fluids

143176 An aeroplane of mass $3 \times 10^{4} \mathrm{~kg}$ and total wing area of $120 \mathrm{~m}^{2}$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in $\mathrm{kPa}$ is $(\mathrm{g}=10$ $\mathbf{m} / \mathbf{s}^{2}$ )

1 2.5
2 5.0
3 10.0
4 12.5
Mechanical Properties of Fluids

143172 The air pressure at sea level is $101325 \mathrm{~Pa}$. At the centre of a rarefaction of a sound wave in air, the pressure is $91000 \mathrm{~Pa}$. Which is the most likely pressure at the centre of a compression of the same wave?

1 $91000 \mathrm{~Pa}$
2 $101000 \mathrm{~Pa}$
3 $111600 \mathrm{~Pa}$
4 $121000 \mathrm{~Pa}$
Mechanical Properties of Fluids

143173 The volumes of containers $A$ and $B$, connected by a tube and a closed valve, are $V$ and $4 V$ respectively. Both the containers $A$ and $B$ have the same ideal gas at pressures (temperatures) $5.0 \times 10^{5} \mathrm{~Pa}(300 \mathrm{~K})$ and $1.0 \times 10^{5} \mathrm{~Pa}(400 \mathrm{~K})$, respectively. The valve is opened to allow the pressure to equalize, but the temperature of each container is kept constant at its initial value. Find the common pressure in the containers

1 $2.5 \times 10^{5} \mathrm{~Pa}$
2 $2.0 \times 10^{5} \mathrm{~Pa}$
3 $3.0 \times 10^{5} \mathrm{~Pa}$
4 $1.5 \times 10^{5} \mathrm{~Pa}$
Mechanical Properties of Fluids

143174 The cylindrical tube of a spray pump has radius $R$, one end of which has $n$ fine holes, each of radius $r$. If the speed of the liquid in the tube is $v$, the speed of the ejection of the liquid through the holes is

1 $\frac{v R^{2}}{n^{2} r^{2}}$
2 \(\frac{\mathrm{vR}^2}{\mathrm{nr}^2}\)
3 $\frac{\mathrm{vR}}{\mathrm{n}^{3} \mathrm{r}^{2}}$
4 $\frac{\mathrm{v}^{2} \mathrm{R}}{\mathrm{nr}}$
Mechanical Properties of Fluids

143175 The pressure on the top surface of an aeroplane wing is $0.8 \times 10^{5} \mathrm{~Pa}$ and the pressure on the bottom surface is $0.75 \times 10^{5} \mathrm{~Pa}$. If the area of each surface is $50 \mathrm{~m}^{2}$, the dynamic lift on the wing is

1 $25 \times 10^{4} \mathrm{~N}$
2 $0.5 \times 10^{4} \mathrm{~N}$
3 $5 \times 10^{4} \mathrm{~N}$
4 $0.25 \times 10^{5} \mathrm{~N}$
Mechanical Properties of Fluids

143176 An aeroplane of mass $3 \times 10^{4} \mathrm{~kg}$ and total wing area of $120 \mathrm{~m}^{2}$ is in a level flight at some height. The difference in pressure between the upper and lower surfaces of its wings in $\mathrm{kPa}$ is $(\mathrm{g}=10$ $\mathbf{m} / \mathbf{s}^{2}$ )

1 2.5
2 5.0
3 10.0
4 12.5