3. We wish to determine the thermal conductivity of an apple (= 950 kg/m3, Cp =...

3. We wish to determine the thermal conductivity of an apple (= 950 kg/m3, Cp = 3200 J/kg K), which can be considered to be a sphere of radius R = 4 cm. To do this, we design an experiment in which a thermocouple is placed at the center of the apple. A rubber sphere of known properties (= 980 kg/m3, Cp = 1910 J/kg K, k = 0.17 W/m K) and the same radius (4 cm) is also provided with a thermocouple placed at its center. Both the apple and the rubber sphere are initially at 25 °C and they are immersed simultaneously in a perfectly-mixed water bath at 75 °C. After a certain time has passed, the two thermocouples read: Apple: 72 °C, rubber sphere: 45 °C. (a) Determine the thermal conductivity of the apple and the time at which the temperature readings were taken. (b) How much thermal energy (J) has been removed from the water bath during this process?

Expert Solution

Amanda K answered 5 months ago

Heat is generated uniformly at a rate of 2x105 W/m3 in a wall of thermal conductivity...

Heat is generated uniformly at a rate of 2x105 W/m3 in a wall of thermal conductivity 25W/m K and thickness 60 mm. The wall is exposed to convection on both sides, with a fluid temperature of 30C and h = 50W/m2 K on the left side, a fluid temperature of 15C and h = 12 W/m2 K on the right side. (a) Determine surface temperature on each side of the wall, and (b) the maximum temperature in the wall.

A stainless steel ball (? = 8055 kg/m3 , CP = 480 J/Kg? K ) of...

A stainless steel ball (? = 8055 kg/m3 , CP = 480 J/Kg? K ) of diameter D = 15cm is removed from the oven at a uniform temperature of 350 Degrees C. The ball is then subjected to the flow of air at 1 atm pressure and 30 degrees C with a velocity of 6m/s. The surface temperature of the ball eventually drops to 250 degrees 250 degrees C. Determine the average convection heat transfer coefficient during this cooling...

Water ( ρ= 1000 kg/m3; Cp= 4.2 kJ/kg.K; k= 0.58 W/m.K ) at 1,537 kg/hr and...

Water ( ρ= 1000 kg/m3; Cp= 4.2 kJ/kg.K; k= 0.58 W/m.K ) at 1,537 kg/hr and 26oC enters a 10-mm-diameter smooth tube whose wall temperature is maintained at 79oC. If the water's Nusselt number (Nu) = 375, and the tube length is 7.6, calculate the water outlet temperature,in oC.

3. A stainless steel sphere of thermal conductivity 16 W/m · K with a diameter of...

3. A stainless steel sphere of thermal conductivity 16 W/m · K with a diameter of 4 cm is exposed to a convective environment of 15 W/m2 · K, 20?C. Heat is generated uniformly in the sphere at a rate of 1.0 MW/m3 . Determine the steady-state temperature of the sphere at its center and its surface. Also determine the heat flux at a radius of 1.5 cm.

3) A piece of metal with a mass of 3.8 kg and density of 1808 kg/m3...

3) A piece of metal with a mass of 3.8 kg and density of 1808 kg/m3 is suspended from a string and then completely immersed in a container of water. The density of water is 1000 kg/m3 . (a) Determine the volume of the piece of metal. (b) Determine the tension in the string after the metal is immersed in the container of water. SHOW ALL WORK AND FORMULAS! THANKS!

We wish to estimate μ , the mean mass (in kg) of the Sandhill Crane. We...

We wish to estimate μ , the mean mass (in kg) of the Sandhill Crane. We take a random sample of 20 Sandhill Cranes and measure their masses. For this sample, we find an average mass of 4.53 kg and a standard deviation of 0.8 kg. Assuming the masses are normally distributed. Find the upper limits of 98% confidence interval for μ . Select the closest to your answer. options: 4.70 5.20 4.90 4.80 5.10 5.00

Determine the terminal settling velocity of a particle having a density of 2540 kg/m3 and a...

Determine the terminal settling velocity of a particle having a density of 2540 kg/m3 and a diameter of 10 mm in water having a temperature of 10C. You may assume that the particle is a perfect sphere (shape factor = 1). What would be the settling velocity for the same particle if the water temperature decreased to 5C?

Consider a turbine; working substance is air. cp=1.0 kJ/kgK , k=1.4 v1=0.03 , v2=0.08 m3/kg , ...

Consider a turbine; working substance is air. cp=1.0 kJ/kgK , k=1.4 v1=0.03 , v2=0.08 m3/kg , p1=2.5 bar; state 1 is enterance, state 2 is the exit of the turbine. The turbine is not ideal (isentropic); the air goes through a state change according to pv^n=constant , n=1.6 Compute the ideal and actual specific works and turbine efficiency. pvn=constant , n=1.6

For H2O, determine the specific volume at the indicated state, in m3/kg. (a) T = 400°C,...

For H2O, determine the specific volume at the indicated state, in m3/kg. (a) T = 400°C, p = 20 MPa. (b) T = 120°C, p = 20 MPa. (c) T = 40°C, p = 2 MPa. I have figured out how to do A, but can't get the correct answer for B or C. All the examples I am finding are with numbers that are listed already on the charts, and mine are not so I need to approach the...

For H2O, determine the specific volume at the indicated state, in m3/kg. (a) T = 480°C,...

For H2O, determine the specific volume at the indicated state, in m3/kg. (a) T = 480°C, p = 20 MPa. (b) T = 160°C, p = 20 MPa. (c) T = 40°C, p = 2 MPa.

Question