Does anyone know this

Answer:

0.0371 kg/s.m

Explanation:

From the given information, let's have an imaginative view of the semi-cylinder; (The image is shown below)

Assuming the base surface of both ends of the cylinder is denoted by:

[tex]A_1 \ and \ A_2[/tex]

Thus, using the summation rule, the view factor [tex]F_{11[/tex] and [tex]F_{12[/tex] is as follows:

[tex]F_{11}+F_{12}=1[/tex]

Let assume the surface (1) is flat, the [tex]F_{11} = 0[/tex]

Now:

[tex]0+F_{12}=1[/tex]

[tex]F_{12}=1[/tex]

However, using the reciprocity rule to determine the view factor from the dome-shaped cylinder [tex]A_2[/tex] to the flat base surface [tex]A_1[/tex]; we have:

[tex]A_2F_{21} = A_{1}F_{12} \\ \\ F_{21} = \dfrac{A_1}{A_2}F_{12}[/tex]

Suppose, we replace DL for [tex]A_1[/tex] and

[tex]A_2[/tex] =  [tex]\dfrac{\pi D}{2}[/tex]

Then:

[tex]F_{21} = \dfrac{DL}{(\dfrac{\pi D}{2}) L} \times 1 \\ \\ =\dfrac{2}{\pi} \\ \\ =0.64[/tex]

Now, we need to employ the use of energy balance formula to the dryer.

i.e.

[tex]Q_{21} = Q_{evaporation}[/tex]

But, before that;  let's find the radian heat exchange occurring among the dome and the flat base surface:

[tex]Q_{21}= F_{21} A_2 \sigma (T_2^4-T_1^4) \\ \\ Q_{21} = F_{21} \times \dfrac{\pi D}{2} \sigma (T_2^4 -T_1^4)[/tex]

where;

[tex]\sigma = Stefan \ Boltzmann's \ constant[/tex]

[tex]T_1 = base \ temperature[/tex]

[tex]T_2 = temperature \ of \ the \ dome[/tex]

∴

[tex]Q_{21} = 0.64 \times (\dfrac{\pi}{2}\times 1.5) \times 5.67 \times 10^4 \times (1000^4 -370^4)\\ \\ Q_{21} = 83899.15 \ W/m[/tex]

Recall the energy balance formula;

[tex]Q_{21} = Q_{evaporation}[/tex]

where;

[tex]Q_{evaporation} = mh_{fg}[/tex]

here;

[tex]h_{fg}[/tex] = enthalpy of vaporization

m = the water mass flow rate

∴

[tex]83899.15 = m \times 2257 \times 10^3 \\ \\ m = \dfrac{83899.15}{ 2257 \times 10^3 }\\ \\ \mathbf{m = 0.0371 \ kg/s.m}[/tex]

The drying rate per unit length is 0.037 kg/S.m

Given data;

From the attached diagram, the surface 1 is flat, it is a view factor, f[tex]_1_1[/tex] = 0.

Applying summation rule and solving the view factor from the base surface A[tex]_1[/tex] to the cylindrical dome A[tex]_2[/tex].

[tex]f_1_1+f_1_2=1[/tex]

Put F[tex]_1_2=0[/tex]

[tex]0+f_1_2=1[/tex]

This makes [tex]f_1_2=1[/tex]

Applying reciprocal rule and solving the view factor from the cylindrical dome A[tex]_2[/tex] to the base surface A[tex]_1[/tex].

[tex]A_2F_2_1=A_1F_1_2\\F_2_1=(\frac{A_1}{A_2})F_1_2[/tex]

Where A is the area of the surface.

Substitute DL for A[tex]_1[/tex] and [tex]\frac{\pi D}{2}[/tex] for A[tex]_2[/tex]

[tex]F_2_1 = \frac{DL}{(\frac{\pi D}{2}})L *1 = \frac{2 }{\pi } =2/3.14 = 0.64[/tex]

Using the energy balance equation to the dryer,

[tex]Q_2_1=Q_e_v_a_p[/tex]

Let's calculate the radiation heat exchange between the dome and the base surface per unit length by using the equation below

[tex]Q_2_1=F_2_1A_2[/tex]δ[tex](T_2^4-T_1^4)[/tex]

[tex]Q_2_1= F_2_1 * \frac{\pi D}{2}[/tex]δ[tex](T_2^4-T_1^4)[/tex]

substitute the respective values into the equation

[tex]Q_2_1=0.64*(\frac{\pi }{2}*1.5)*5.67*10^-^8*(1000^4-370^4)\\Q_2_1=8.3899.15W/m[/tex]

Let's calculate the mass flow rate of water using the amount of heat required for drying up.

[tex]Q_2_1=Q_e_v_a_p\\Q_e_v_a_p=mh_f_g\\[/tex]

where [tex]h_f_g= 2257*10^3J/kg[/tex]

and this is the enthalpy of vaporization and mass flow rate of water.

[tex]83899.15=m*2257*10^3\\m=0.037kg/S.m[/tex]

The drying rate per unit length is 0.037kg/S.m

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Look at the load capacity chart in the cab

Explanation:

A crane can be defined as a large, tall metallic machine or equipment that is designed with a long horizontal arm (jib) used for the lifting and movement of very heavy objects through the air. They're usually designed to be operated by a human operator, who typically uses a remote controller and a beam to control the direction of movement of the crane.

Due to the fact that cranes are used for lifting and moving very heavy objects, they are powered by an internal combustion engine and electric motors.

Furthermore, all cranes have the maximum capacity of load they're able to lift at a particular point in time. In order to determine the rated or gross capacity of a crane and maintain safe operation, it is important to check its load capacity chart. The actual load a crane can lift is its net capacity and it must not be exceeded at any time, so as to avoid structural failure or overturning of the crane.

Hence, the best way to find the load capacity of a crane is to look at the load capacity chart in the cab.

The load can include rigging components, hooks, blocks, and other lifting equipment that is considered part of the load. The maximum load capacity of the crane is about 18 metric tons.

Hence the option C look at the chart is correct.

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