At a festival, spherical balloons with a radius of 140.cm are to be inflated with hot air and released. The air at the festival
will have a temperature of 25°C and must be heated to 100°C to make the balloons float. 1.00kg of propane C3H8 fuel are available to be burned to heat the air. Calculate the maximum number of balloons that can be inflated with hot air. Here are some data you may find useful: Specific heat capacity of air: 1.009J·g°C Density of air at 100°C: 0.946kgm3 Density of propane at 100°C: 1.440kgm3 Formation enthalpy of propane at 25°C: −103.85kJmol
1 answer:
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Answer:
2.135
Explanation:
Lets make use of these variables
Ox 16.5 kpsi, and Oy --14,5 kpsi
To determine the factor of safety for the states of plane stress. We have to first understand the concept of Coulomb-Mohr theory.
Mohr–Coulomb theory is a mathematical model describing the response of brittle materials such as concrete, or rubble piles, to shear stress as well as normal stress.
Please refer to attachment for the step by step solution.
Answer:
The governing ratio for thin walled cylinders is 10 if you use the radius. So if you divide the cylinder´s radius by its thickness and your result is more than 10, then you can use the thin walled cylinder stress formulas, in other words:
- if
then you have a thin walled cylinder
or using the diameter:
- if
then you have a thin walled cylinder
Answer:
the heat transfer from the pipe will decrease when the insulation is taken off for r₂<
where;
r₂ = outer radius
= critical radius
Explanation:
Note that the critical radius of insulation depends on the thermal conductivity of the insulation k and the external convection heat transfer coefficient h .
The rate of heat transfer from the cylinder increases with the addition of insulation for outer radius less than critical radius (r₂< ) 0, and reaches a maximum when r₂ =
, and starts to decrease for r₂<
. Thus, insulating the pipe may actually increase the rate of heat transfer from the pipe instead of decreasing it when r₂<
.