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3 years ago

You are preparing to exit from an expressway. You should begin slowing to the posted safe

Engineering

2 answers:

wlad13 [49]3 years ago

8 0

Answer:

Your answer will be B: At least 100 feet after leaving the expressway

maria [59]3 years ago

5 0

Answer:

The answer is B. At least 100 feet after leaving the expressway.

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4. Fill in the blanks with the words from the Word Bank below.

lyudmila [28]

Answer:

space race

cold war

lunar module

mission control

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3 years ago

What are the 5 major forest types?

Nataly [62]

Answer:

1. Equatorial Evergreen or Rainforest

2. Tropical forest

3. Mediterranean forest

4. Temperate broad-leaved forest

5. Warm temperate forest

Explanation:

4 0

4 years ago

Read 2 more answers

PLEASE HELP ME!!!!!! IM LOW ON POINTS BUT I NEED SOME HELP, QUICK!!! POINTS FOR HELPFUL ANSWERS + BRAINLIEST!!!!!

meriva

Answer:

Kitchen sinks can be clogged for a few reasons, food hair, and other things. Overtime, buildup of these things lead to clogging.

A few methods to fix clogging are, baking soda mixture, plunging, and boiling water.

The first method, baking soda mixture, what you do is you pour a cup of baking soda and vinegar down the drain, and place a rubber stopper to cover the drain opening. Wait 10 or more minutes, and take out the stopper, and run hot tap water until it's unclogged.

The second method is plunging. Make sure the sink has enough water to submerge the plunger, and start plunging. While you are plunging, maintain a good seal to get the best results. This usually works, but sometimes it doesn't.

The last method is boiling water. Pour boiling water into the drain, then after a while, the clogged drain should unclog, if it doesn't repeat the process until necessary.

Explanation:

8 0

3 years ago

A specimen of a 4340 steel alloy with a plane strain fracture toughness of 54.8 MPa (50 ksi ) is exposed to a stress of 2023 MPa

Neko [114]

Answer:

Explanation:

The formula for critical stress is

$\sigma_c=\frac{K}{Y\sqrt{\pi a} }$

$\sigma_c =\texttt{critical stress}$

K is the plane strain fracture toughness

Y is dimensionless parameters

We are to Determine the Critical stress

Now replacing the critical stress with 54.8

a with 0.2mm = 0.2 x 10⁻³

Y with 1

$\sigma_c=\frac{54.8}{1\sqrt{\pi \times 0.2\times10^{-3}} } \\\\=\frac{54.8}{\sqrt{6.283\times10^{-4}} } \\\\=\frac{54.8}{0.025} \\\\=2186.20Mpa$

The fracture will not occur because this material can handle a stress of 2186.20Mpa before fracture. it is obvious that is greater than 2023Mpa

Therefore, the specimen does not failure for surface crack of 0.2mm

4 0

3 years ago

A 900 kg car is accelerated from a speed of 10 m/s to 30 m/s. An estimated heat loss of 20 BTU's occurs during the acceleration.

Strike441 [17]

Answer:

Work = 651,1011 kJ

Explanation:

Let´s take the car as a system in order to apply the first law of thermodynamics as follows:

$E_{in}- E_{out}=E_{system,final}- E_{system,initial}$

Where

$E_{in}- E_{out}=(Q_{in}-Q_{out})_{heat}+(W_{in}-W_{out})_{work}+(Em_{in}-Em_{out})_{mass}$

And considering that there is no mass transfer and that the only energy flows that interact with the system are the heat losses and the work needed to move the car we have:

$E_{in}- E_{out}=-Q_{out}+W_{in}$

Regarding the energy system we have the following:

$E_{system,final}- E_{system,initial}=(U_{f}-U_{i})_{internal}+(1/2m(V^2_{f}-V^2_{i}))_{kinetic}+(mg(h_{f}-h_{i}))_{potential}$

By doing the calculations we have:

$E_{system,final}- E_{system,initial}=[0,1*900]_{internal}+[0,5*900(30^2-10^2)/1000)_{kinetic}+(900*10*(20-0)/1000)_{potential}\\E_{system,final}- E_{system,initial}=90+360+180=630kJ$

Consider that in the previous calculation, the kinetic and potential energy terms were divided by 1.000 to change the units from J to kJ.

Finally, the work needed to move the car under the required conditions is calculated as follows:

$W_{in}=Q_{out}+E_{system,final}- E_{system,initial}\\W_{in}=21,1011+630=651,1011kJ$

Consider that in the previous calculation, the heat loss was changed previously from BTU to kJ.

4 0

3 years ago