This is a classification of back pain based on duration. A) AcuteB) RecurrentC) ChronicD) All of the above

Which of the following would not be considered hot work? A chipping B soldering C

tankabanditka [31]

I believe the answer is D: brazing
Hope this helps you have a good night

5 0

3 years ago

The screw of shaft straightener exerts a load of 30 as shown in Figure . The screw is square threaded of outside diameter 75 mm

kykrilka [37]

Answer:

See calculation below

Explanation:

Given:

W = 30 kN = 30x10³ N

d = 75 mm

p = 6 mm

D = 300 mm

μ = tan Φ = 0.2

1. Force required at the rim of handwheel 

Let P₁ = Force required at the rim of handwheel

Inner diameter or core diameter of the screw = dc = do - p = 75 - 6 = 69 mm

Mean diameter of screw: *d = $\frac{do + dc}{2}$ = (75 + 69) / 2 = 72 mm

and

tan α = p / πd = 6 / (π x 72) = 0.0265

∴ Torque required to overcome friction at he threads is T = P x d/2

T = W tan (α + Ф) d/2

T = $W(\frac{tan \alpha + tan \theta}{1 - tan \alpha + tan \theta } ) * \frac{d}{2}$

T = 30x10³ * ((0.0265 + 0.2) / (1 - 0.0265 x 0.2)) x 72/2

T = 245,400 N-mm

We know that the torque required at the rim of handwheel (T)

245,400 = P1 x D/2 = P1 x (300/2) = 150 P1

P1 = 245,400 / 150

P1 = 1636 N

2. Maximum compressive stress in the screw

30x10³

Qc = W / Ac = -------------- = 8.02 N/mm²

π/4 * 69²

Qc = 8.02 MPa

Bearing pressure on the threads (we know that number of threads in contact with the nut)

n = height of nut / pitch of threads = 150 / 6 = 25 threads

thickness of threads, t = p/2 = 6/2 = 3 mm

bearing pressure on the threads = Pb = W / (π d t n)

Pb = 30 x 10³ / (π * 72 * 3 * 25)

Pb = 1.77 N/mm²

Max shear stress on the threads = τ = 16 T / (π dc³)

τ = (16 * 245,400) / ( π * 69³ )

τ = 3.8 M/mm²

*the mean dia of the screw (d) = d = do - p/2 = 75 - 6/2 = 72

∴max shear stress in the threads τmax = 1/2 * sqrt(8.02² + (4 * 3.8²))

τmax = 5.5 Mpa

3. efficiency of the straightener

To = W tan α x d/2 = 30x10³ * 0.0265 * 72/2 = 28,620 N-mm

∴Efficiency of the straightener is η = To / T = 28,620 / 245,400

η = 0.116 or 11.6%

4 0

3 years ago

Describe the algorithm you use for looking up a person’s telephone number in the phone book. The input is person’s name; the out

Stella [2.4K]

Answer:

The Algorithm for finding a number from a phone book with the person's name as the input and the phone number as output is as follows:

1. Try to remember the name, i.e last name first and first name last, Also make sure you get the spelling right.

2. Using the first letter of the last name, locate the appropriate alphabetical section in which the name should appear.

3. Using the second letter of the last name, find the subsection of first and second letters combined, in the appropriate order, in which the name should appear. (If the last name consists of only two letters, find the appropriate first name.)

4. Using the third letter, find the possible names in a subsection of the first three letters in the correct order. Continue this step with x+1 letters of the name until you have a subsection of names exactly matching the last name of the person whose number you are trying to locate. (x is the number of letters used in the previous step, consistently.) If there is only one of the last name, (check for duplicates) identify the number, and return phone number information.

5. Begin the second step using the first letter of the first name, but limit the section to only those exactly matching the last name. Continue to step 4, again focusing on the first name only within the set of exactly matching last names.

6. When both first and last name match the name you are locating, check for duplicates. IF there are no duplicates, return phone number information.

Explanation:

People's names are generally arranged in phone books in alphabetical order by the last name of the person. The first name of the person is listed after the last name so that people of the same last name can be differentiated.

7 0

4 years ago

Read 2 more answers

Which of the following uses pressure and flow to transmit power from one location to another?

lord [1]

Answer:

fluid power

Explanation:

fluids commonly used in fluid power are Oil, Water, Air, CO², and Nitrogen gas, fluid power is commonly confused with hydraulic power, which only uses liquids, fluid power uses either liquids or gases

5 0

2 years ago

Health Maintenance Organizations (HMOs) are the new model for providing medical care. Criticisms of HMOs include all of the foll

Tema [17]

Answer:

c. multiple trips to many specialists.

Explanation:

These are a organizations that provide health insurance time fee.

7 0

4 years ago