A capillary tube of 1.2 mm diameter is immersed vertically in water exposed to the atmosphere. Determine how high water will rise in the tube. Take the contact angle at the inner wall of the tube to be $6^{\circ}$ and the surface tension to be 1.00 N/m.

capillary tube is immersed vertically in a water container. Knowing that water starts to evaporate when the pressure drops below 2 kPa, determine the maximum capillary rise and tube diameter for this maximum-rise case. Take the contact angle at the inner wall of the tube to be $6^\circ$ and the surface tension to be 1.00 N/m.

What is forced convection? How does it differ from natural convection? Is convection caused by winds forced or natural convection?

Use the values given for each function. Does the second derivative of the function appear to be positive or negative over the given interval? Explain.

$$\begin{matrix} \text{t} & \text{0} & \text{1} & \text{2} & \text{3} & \text{4} & \text{5}\\ \text{s(t)} & \text{12} & \text{14} & \text{17} & \text{20} & \text{31} & \text{55}\\ \end{matrix}$$

Consider a 0.15-mm diameter air bubble in a liquid. Determine the pressure difference between the inside and outside of the air bubble if the surface tension at the air-liquid interface is (a) 0.080 N/m and (b) 0.12 N/m.

Consider a 0.15 -mm-diameter air bubble in a liquid. Determine the pressure difference between the inside and outside of the air bubble if the surface tension at the air-liquid interface is

(a) 0.080 N / m and

(b) 0.12 N / m.

The viscosity of a fluid is to be measured by a viscometer constructed of two 75 -cm-long concentric cylinders. The outer diameter of the inner cylinder is 15 cm, and the gap between the two cylinders is 1 mm. The inner cylinder is rotated at 300 rpm, and the torque is measured to be $0.8 N \cdot m$. Determine the viscosity of the fluid.

A fluid that occupies a volume of 24 L weighs 225 N at a location where the gravitational acceleration is $9.80 m/s^2.$ Determine the mass of this fluid and its density.

Consider a soap bubble. Is the pressure inside the bubble higher or lower than the pressure outside?

The tube rests on a $1.5$-$\mathrm{mm}$ thin film of oil having a viscosity of $\mu=0.0586 \mathrm{~N} \cdot \mathrm{s} / \mathrm{m}^2$. If the tube is rotating at a constant angular velocity of $\omega=4.5\ \mathrm{rad} / \mathrm{s}$, find the shear stress in the oil at $r=40 \mathrm{~mm}$ and $r=80 \mathrm{~mm}$. Assume the velocity profile within the oil is linear.

Determine the speed of sound in air at (a) 300 K and (b) 800 K. Also determine the Mach number of an aircraft moving in air at a velocity of 330 m/s for both cases.

A capillary tube is immersed vertically in a water container. Knowing that water starts to evaporate when the pressure drops below 2 kPa, determine the maximum capillary rise and tube diameter for this maximum-rise case. Take the contact angle at the inner wall of the tube to be 6 degree and the surface tension to be 1.00 N / m

Consider two identical small glass balls dropped into two identical containers, one filled with water and the other with oil. Which ball will reach the bottom of the container first? Why?

A thin 30 -cm $\times$ 30-cm flat plate is pulled at 3 m/s horizontally through a 3.6 -mm-thick oil layer sandwiched between two plates, one stationary and the other moving at a constant velocity of 0.3 m/s. The dynamic viscosity of the oil is 0.027 Pa $\cdot$ s. Assuming the velocity in each oil layer to vary linearly,

(a) plot the velocity profile and find the location where the oil velocity is zero and

(b) determine the force that needs to be applied on the plate to maintain this motion.