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2 years ago

Read the following tip. "If your answer is not among the choices, try writing it

Engineering

1 answer:

m_a_m_a [10]2 years ago

7 0

<h3>Option D</h3>

Multiple-choice questions on the math section of the PSAT

could you use this tip

<h3><u>Explanation:</u></h3>

The Preliminary SAT is a rehearsal version of the SAT exam. If you gain a huge score on the PSAT, you could pass to obtain a National Merit Scholarship. It is concentrated on the abilities and experience at the heart of learning. Most math problems will be multiple-choice, but any—called student-produced answers—request you to develop up with the answer moderately than pick the answer.

The multiple-choice questions produce four feasible answers; learners must decide which of the four choices is the suitable answer to the question. All multiple-choice questions are counted the same way: one point for every right solution and zero points for wrong interpretations.

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Your roommate wants to learn about organizational chart. You can tell her that these charts can tell you all of these about an o

mars1129 [50]

Answer:

Control mechanisms

Explanation:

Organizational chart of any company will give details of different aspects of the company such as the major sub-units of the organization with the names of team leaders for different sub-units, it can also give you the span of control and the division of work within the company. However, the chart can't show you control mechanisms of different departments.

4 0

2 years ago

You work in Madison, Wisconsin. It is January and the area has been hit with bad weather. Another weather front is expected to a

Lelu [443]

Answer:

The best first sentence of your e-mail will be-

<u>Weather forecasters are predicting a blizzard this afternoon, so, as a result of this news, our supervisor has decided to close the office at noon so people can travel home safely.</u>

<u />

5 0

2 years ago

Radioactive wastes are temporarily stored in a spherical container, the center of which is buried a distance of 10 m below the e

puteri [66]

Given:

outer radius, R' = 10 m

inner diameter, d = 2 m

inner radius, R = $\frac{d}{2}$ = 1 m

surface temperature, T' = $20^{\circ}C$

Thermal conductivity of soil, K = 0.52 W/mK

Solution:

To calculate the thermal temperature of conductor, T, we know amount of heat, Q is given by :

Q = $\frac{T - T'}{\frac{R' - R}{4\pi KRR'}}$

500 = $(T - 20)\frac{4\pi \times0.52\times 1\times 10}{10 - 1}$

T = 68.86 +20 = $88.865^{\circ}C$

Therefore, outside surface temperature is $88.865^{\circ}C$

4 0

2 years ago

Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider the reheat stage for a 100-m

kodGreya [7K]

Complete question is;

Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider the reheat stage for a 100 mm thick plate (ρ = 7830 kg/m3, Cp = 550 J/kg K, k = 48 W/m K). The plate initially is at 200 °C and is to be heated to a minimum temperature of 550 °C. Heating is effected in a gas-fired furnace where the products of combustion at T∞ = 800 °C maintain a convection heat transfer coefficient of h = 250 W/m.K on both surfaces of the plate. How long should the plate be left in the furnace?

Answer:

860 seconds

Explanation:

We are given;

Initial Temperature; Ti = 200 °C

Minimum Temperature; T_i = 550 °C

T∞ = 800 °C

convection coefficient; h = 250 W/m².K

ρ = 7830 kg/m³

Cp = 550 J/kg K

k = 48 W/m K

Plate thickness = 100mm

Thus,L = 100/2 = 50mm = 0.05 m

Let's find the biot number from the formula;

Bi = hL/K

Bi = (250 × 0.05)/48

Bi = 0.2604

Now, lowest temperature in the slab is given as;

θ_o = (T_o - T∞)/(T_i - T∞)

θ_o = (550 - 800)/(200 - 800)

θ_o = 0.4167

Now, from online tables calculation, we can find the root of the biot number.

Thus, root of the biot number Bi = 0.2604 is;

ζ1 = 0.488 rad

Also, C1 is gotten as 1.0396

Now,formula for thermal diffusivity is;

α = k/ρc

α = 48/(7830 × 550)

α = 1.115 × 10^(-5) m²/s

Also, from online tables, f(ζ1) = 0.401

Thus, we can find the time the plate should the plate be left in the furnace from;

-(ζ1)²(αt/L²) = In 0.401

-(ζ1)²(αt/L²) = -0.9138

t = (-0.9138 × 0.05²)/-(0.488² × 1.115 × 10^(-5))

t ≈ 860 s

8 0

2 years ago

A six- lane freeway ( three lanes in each direction) in a scenic area has a measured free- flow speed of 55 mi/ h. The peak- hou

Novosadov [1.4K]

Answer:

0.867

Explanation:

The driver population factor ( $f_{p}$ )can be estimated using the equation below:

$f_{p} = \frac{V}{PHF*N*f_{HV}*v_{p}}$

The value of the heavy vehicle factor ( $f_{HV}$ ) is determined below:

The values of the $E_{T}$ = 2 and $E_{R}$ = 3 are gotten from the tables for the RVs, trucks and buses upgrades for passenger-car equivalents. Therefore:

$f_{HV}$ = 1/[1+0.08(2-1)+0.06(3-1)] = 1/[1+0.08+0.12] = 1/1.2 = 0.833

Furthermore, the vp is taken as 2250 pc/(h*In) from the table of LOS criteria for lane freeway using the 15 minutes flow rate. Therefore:

$f_{p}$ = 3900/[0.8*3*0.833*2250] = 3900/4498.2 = 0.867

6 0

2 years ago