Engineering, 14.04.2020 18:12 j015

To warm up some milk for a baby, a mother pours milk into a thin-walled glass whose diameter is 6 cm> the height of glass is 7 cm. She then places the glass into a large pan filled with hot water at 70oC. The milk is stirred constantly, so that its temperature is uniform at all times. If the heat transfer coefficient between the water and glass is 120 W/m2K, determine how long it will take to warm up from 3oC to 38oC. Take all the properties of milk to be the same as those of water.

Answers: 1

Show answers

Another question on Engineering

Engineering, 03.07.2019 14:10

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

Answers: 2

Answer

Engineering, 04.07.2019 18:10

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Answers: 3

Answer

Engineering, 04.07.2019 18:20

Air flows over a heated plate àt a velocity of 50m/s. the local skin factor coefficient at a point on a plate is 0.004. estimate the local heat transfer coefficient at this point.the following property data for air are given: density = 0.88kg/m3 , viscosity 2.286 x 10 ^-5 kgm/s , k = 0.035w/mk ,cp = 1.001kj/kgk. use colburn reynolds analogy.

Answers: 1

Answer

Engineering, 04.07.2019 18:20

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.

Answers: 1

Answer

You know the right answer?

To warm up some milk for a baby, a mother pours milk into a thin-walled glass whose diameter is 6 cm...

Questions