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3 years ago

Which vegetation type do you think will cause fire to spread the fastest?

Engineering

1 answer:

Ivan3 years ago

7 0

Answer:B

Explanation: Dead Grass more flammable than wood and Green grass contains water.

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A structural element for a new bridge is designed for a constant load of 1000 psi. Its mean resistance is 1200 psi and the proba

andrew11 [14]

Answer:

i) SF = 0.83

ii) 10 psi

iii) 3.16 psi

iv) 0.0083

Explanation:

Constant load = 1000 Psi

mean resistance = 1200 psi

Probability of failure = 1.9 * 10^-3

Determine

i) Safety factor

S.F = 1 / (mean load / load design ) = 1 / ( 1200 / 1000 ) = 0.83

ii) Standard deviation

1.9 X 10^-3 = e ( -1/2 ( μ / б) ^3 / (2.5 * 6 )

0.004756 = e^- 20000 / б^3

hence std = 10 psi

iii) Variance

= $\sqrt{10}$ = 3.16 psi

iv) coefficient of variation

Cv = std / mean resistance

= 10 / 1200 = 0.0083

4 0

3 years ago

Consider steady heat transfer through the wall of a room in winter. The convection heat transfer coefficient at the outer surfac

AveGali [126]

The heat transfer which is in steady state, the heat transfer rate to the wall is equal to the wall.

Explanation:

The convection transfer of heat to the wall is

$Q=h A\left(T_{s}-T_{f}\right)$

Here, $T_{S}$ is the temperature of solid surface, $T_{f}$ is the temperature of moving fluid stream which is adjacent of solid surface, h is the heat transfer coefficient.
The coefficient of convection heat transfers outer surface contains 3 times to the inner surface which experience smaller drop of temperature for 3 times that compares to inner surface.
Hence, the temperatures outer surface get close to the surroundings of air temperature.

6 0

3 years ago

Which professional draws maps and plans for projects involving structures other than buildings, such as bridges?

kolbaska11 [484]

Answer:

I believe it is a civil drafter

Explanation:

O*NET site

3 0

4 years ago

Read 2 more answers

An automobile tire with a volume of 0.8 m3 is inflated to a gage pressure of 200 kPa. Calculate the mass of air in the tire if t

saveliy_v [14]

Answer:

2.83 kg

Explanation:

Given:

Volume, V = 0.8 m³

gage pressure, P = 200 kPa

Absolute pressure = gage pressure + Atmospheric pressure

= 200 + 101 = 301 kPa = 301 × 10³ N/m²

Temperature, T = 23° C = 23 + 273 = 296 K

Now,

From the ideal gas equation

PV = mRT

Where,

m is the mass

R is the ideal gas constant = 287 J/Kg K. (for air)

thus,

301 × 10³ × 0.8 = m × 287 × 296

m = 2.83 kg

3 0

4 years ago

a turbine operating at steady state at 500 kPa, 860 K and exists at 100 kPa. A temperature sensor indicates that the exit air te

noname [10]

Answer:

Given:

P₁ = 500 kPa

T₁ = 860 K

P₂= 100 kPa

T₂ = 460 K

Let's take entropy properties of T1 and T2 from ideal properties of air,

at T = 860K, s(T₁) = 2.79783 kJ/kg.K

at T = 460K, s(T₂) = 2.13407 kJ/kg.K

using entropy balance equation:

$\frac{\sigma _cv}{m} = s(T_2)- s(T_1) - R In [\frac{P_2}{P_1}]$

$\frac{\sigma _cv}{m} = 2.79783 - 2.13407 - 0.287 In [\frac{100}{500}]$

= - 0.2018 kJ/kg. K

In this case the entropy is negative, which means the value of exit temperature is not correct, beacause entropy should always be positive(>0).

8 0

3 years ago