A graduated cylinder full of water in the lab on a bench that has just been waxed. The cylinder is 1 cm^2 in the inner cross-sectional area, and the water is 10 cm high. The temperature is at room temperature (25 °C) and remains constant. Water-air interface energy (i.e., water surface tension) is approximately 0.072 N/m at 25 °C. All the water spills and forms a puddle that can be approximated as a thin disk. (a) If this disk’s diameter is 14 cm, calculate the work required to create just the air-water interface. (b) Calculate the change in the gravitational potential energy of the water puddle in (b) (g = 9.8 m/s2

A graduated cylinder full of water in the lab on a bench that has just been waxed. The cylinder is 1 cm^2 in the inner cross-sectional area, and the water is 10 cm high. The temperature is at room temperature (25 °C) and remains constant. Water-air interface energy (i.e., water surface tension) is approximately 0.072 N/m at 25 °C. All the water spills and forms a puddle that can be approximated as a thin disk. (a) If this disk’s diameter is 14 cm, calculate the work required to create just the air-water interface. (b) Calculate the change in the gravitational potential energy of the water puddle in (b) (g = 9.8 m/s2

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.9P: When a sphere falls freely through a homogeneous fluid, it reaches a terminal velocity at which the...

See similar textbooks

Similar questions

PROPAGATION OF ERROR You are tasked to supervise the design of 0.5MW wind turbine to be constructed in a Wind Farm in Pililla, Rizal. Suppose the design criteria are as follows: The air density as surveyed after 2 year period averaged at 1.225 kg / cubic meter. The sweeping diameter of the rotor blades is 125m, and the anemometer reading in the area amounts to 4.2m/s on a 2 year period of survey. if the diameter measurement is off by 0.1m and the anemometer reading is also fluctuating by 0.05m/s. In the design specifications given, if the actual measurement of power via the substation amounts to exactly 530kW and given that the windspeed is off by 0.05m/s, what could have been the error in the measurement of diameter? Your answer must be in 3 decimal places and in correct signs and measurement. Show complete solution in paper.
EXAMPLE Leaking Tank. Outflow of Water Through a Hole (Torricelli's Law) This is another prototype engineering problem that leads to an ODE. It concerns the outflow of water from a cylindrical tank with a hole at the bottom. You are asked to find the height of the water in the tank at any time if the tank has diameter 2 m, the hole has diameter 1 cm, and the initial height of the water when the hole is opened is 2.25 m. When will the tank be empty? 2.20 M Water level asime Outiine walls 200 200 30t .00- 50- D 10000 30000 tebe Revelion 50000
"You are tasked to supervise the design of 0.5MW wind turbine to be constructed in the Wind Farm in Pililla, Rizal. Suppose the design criteria are as follows: The air density as surveyed after 2 year period averaged at 1.225 kg / cubic meter; the sweeping diameter of the rotor blades is 125m; and the anemometer reading in the area amounts to 4.2m/s on a 2 year period of survey. What is the theoretical power output of the turbine assuming 100% efficiency of operation? Your answer must be in kW and in two decimal places with correct signs." In the previous problem, if the diameter measurement is off by 0.1m and the anemometer reading is also fluctuating by 0.05m/s and if the error measurement for theoretical power output must be limited to 3%, WHY OR WHY NOT should you accept the design?
When a clean glass tube with a diameter of 2 mm is immersed in water at 20 ° C, how many mm will the capillary rise occur in the glass tube? For water at 20 ° C, surface tension is given as 0.073 N / m, density 1000 kg / m3, contact angle 0 ° C and gravitational acceleration 10 m / s2.
When a person ice skates, the surface of the ice actuallymelts beneath the blades, so that he or she skates on a thinsheet of water between the blade and the ice.( a ) Find an expression for total friction force on the bottomof the blade as a function of skater velocity V , bladelength L , water thickness (between the blade and theice) h , water viscosity μ , and blade width W .( b ) Suppose an ice skater of total mass m is skatingalong at a constant speed of V 0 when she suddenlystands stiff with her skates pointed directly forward,allowing herself to coast to a stop. Neglecting frictiondue to air resistance, how far will she travelbefore she comes to a stop? (Remember, she iscoasting on two skate blades.) Give your answer forthe total distance traveled, x , as a function of V 0 , m ,L , h , μ , and W .( c ) Find x for the case where V 0 = 4.0 m/s, m = 100 kg,L = 30 cm, W = 5.0 mm, and h = 0.10 mm. Do youthink our assumption of negligible air resistance is agood one?
Aiming a 1.69 in diameter garden hose straight up, forms a “bubbler fountain” that you could easily drink from (but you shouldn’t because of bacteria, etc.). The water flows out the hose and down the sides. If the water has a density of 63.1 lbm/ft^3 and a viscosity of 0.0119 g/cm*s, what is the thickness of the water film (df) (in cm) if the flow rate of water is 6.42 in^3/s? For simplicity, assume the film is thin enough that you can use rectangular coordinates.
The pressure in a water tower is 27,030 Pascals (N / (m ^ 2)) higher than at an open faucet. The density of water is 1000Kg / (m ^ 3). Use Bernoulli's equation to determine the velocity of outflow from the open faucet. the height difference between the top water level in the tower and the faucet is 9 meters, then the velocity of outflow is
The density of a fluid is given by the empirical equation: ? = 70.5exp(8.27×10^−7 ?), where ? is density (lbm/ft^3) and P is pressure (lbf/in^2). a) Calculate the density in g/cm^3 for a pressure of 9.00 x 10^ 6 N/m^2.c) Derive a formula for ? (g/cm^3) as a function of P (N/m^2).
Find the size of a wind turbine rotor (diameter in m) that will generate 100kW of electrical power in a steady wind (hub height) of 7.5 m/s. Assume that the air density is 1.225 kg/m3, Cp = 16/27 and n = 1. %3D
(You are tasked to supervise the design of 0.5MW wind turbine to be constructed in the Wind Farm in Pililla, Rizal. Suppose the design criteria are as follows: The air density as surveyed after 2 year period averaged at 1.225 kg / cubic meter; the sweeping diameter of the rotor blades is 125m; and the anemometer reading in the area amounts to 4.2m/s on a 2 year period of survey. What is the theoretical power output of the turbine assuming 100% efficiency of operation? Your answer must be in kW and in two decimal places with correct signs) In the design specifications given, if the actual measurement of power via the substation amounts to exactly 530kW and given that the windspeed is off by 0.05m/s, what could have been the error in the measurement of diameter? Your answer must be in 3 decimal places and in correct signs and measurement.
A viscous fluid of density 1200 kg/m3 and viscosity 0.9 Pa.s is confined in a spacing of 0,01 m between two parallel and horizontal plates of length 0,6 m and width 0,6 m. The upper plate is pulled with a uniform and steady speed of 0,7 m/s in its own plane. The lower plate is stationary. Viscous fluid flow is laminar steady and incompressible. a) What is the magnitude of mass flow rate in spacing (in kg/s)? b) What is the magnitude of maximum shearing stress in the flow field (in Pa)? c) What is the frictional force over the lower plate surface (in N )? d) What is the frictional power lost in pulling the upper plate (in W)?
The volume flow Q over a certain dam is a function of damwidth b , gravity g , and the upstream water depth H abovethe dam crest. It is known that Q is proportional to b . If b=120 ft and H =15 in., the flow rate is 600 ft 3 /s. What willbe the flow rate if H = 3 ft?