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2 years ago

Fill in the Blank: When using a standard cold chisel, be sure the end is grounded to a sharp point at a _____ degree angle.

Engineering

1 answer:

jok3333 [9.3K]2 years ago

5 0

Answer:

25°

Explanation:

At the factory, a standard cold chisel are ground to 25° which is appropriate for the various works performed by a chisel. However, A chisel with a 30° cutting edge is advisable to users because it will help the edge to last longer.

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CHALLENGE ACTIVITY 2.8.1: Using constants in expressions. The cost to ship a package is a flat fee of 75 cents plus 25 cents per

mihalych1998 [28]

Answer:

Weight(lb): 10

Flat fee(cents): 75

Cents per pound: 25

Shipping cost(cents): 325

Explanation:

we run this as a jave programming language

import java.util.Scanner;

public class Shipping Calculator {

public static void main (String [] args) {

int shipWeightPounds = 10;

int shipCostCents = 0;

final int FLAT_FEE_CENTS = 75;

final int CENTS_PER_POUND = 25;

shipCostCents = FLAT_FEE_CENTS + CENTS_PER_POUND * shipWeightPound

/* look up the solutioin above */

System.out.println("Weight(lb): " + shipWeightPounds);

System.out.println("Flat fee(cents): " + FLAT_FEE_CENTS);

System.out.println("Cents per pound: " + CENTS_PER_POUND);

System.out.println("Shipping cost(cents): " + shipCostCents);

}

7 0

2 years ago

A thin-walled tube with a diameter of 12 mm and length of 25 m is used to carry exhaust gas from a smoke stack to the laboratory

nlexa [21]

Answer:

(a) h₁ = 204.45 W/m²k

(b) h₀ = 46.80 W/m².k

Explanation:

Given Data;

Diameter = 12mm

Length = 25 m

Entry temperature = 200°C

Flow rate = 0.006 kg/s

velocity = 2.5 m/s.

Step 1: Calculating the mean temperature;

(200 + 15)/2

Mean temperature = 107.5°C = 380.5 K

The properties of air at mean temperature 380.5 K are given as:

v = 24.2689*10⁻⁶m²/s

a = 35.024*10⁻⁶m²/s

μ = 221.6 *10⁻⁷Ns/m²

k = 0.0323 W/m.k

Cp = 1012 J/kg.k

Step 2: Calculating the prantl number using the formula;

Pr = v/a

= 24.2689*10⁻⁶/ 35.024*10⁻⁶

= 0.693

Step3: Calculating the reynolds number using the formula;

Re = 4m/πDμ

= 4 *0.006/π*12*10⁻³ * 221.6 *10⁻⁷

= 0.024/8.355*10⁻⁷

= 28725

Since Re is greater than 2000, the flow is turbulent. Nu becomes;

Nu = 0.023Re^0.8 *Pr^0.3

Nu = 0.023 * 28725^0.8 * 0.693^0.3

= 75.955

(a) calculating the heat transfer coefficient:

Nu = hD/k

h = Nu *k/D

= (75.955 * 0.0323)/12*10^-3

h = 204.45 W/m²k

(b)

Properties of air at 15°C

v = 14.82 *10⁻⁶m²/s

k = 0.0253 W/m.k

a = 20.873 *10⁻⁶m²/s

Pr(outside) = v/a

= 14.82 *10⁻⁶/20.873 *10⁻⁶

= 0.71

Re(outside) = VD/v

= 2.5 * 12*10⁻³/14.82*10⁻⁶

=2024.29

Using Zakauskus correlation,

Nu = 0.26Re^0.6 * Pr^0.37 * (Pr(outside)/Pr)^1/4

= 0.26 * 2024.29^0.6 * 0.71^0.37 * (0.71/0.693)^1/4

= 22.199

Nu = h₀D/k

h₀ = Nu*k/D

= 22.199* 0.0253/12*10⁻³

h₀ = 46.80 W/m².k

(c)

Calculating the overall heat transfer coefficient using the formula;

1/U =1/h₁ +1/h₀

1/U = 1/204.45 + 1/46.80

1/U = 0.026259

U = 1/0.026259

U = 38.08

Calculating the temperature of the exhaust using the formula;

T -T₀/T₁-T₀ = e^-[uπDL/Cpm]

T - 15/200-15 = e^-[38.08*π*12*10⁻³*25/1012*0.006]

T - 15/185 = e^-5.911

T -15 = 185 * 0.002709

T = 15+0.50

T = 15.50°C

6 0

2 years ago

The small washer is sliding down the cord OA. When it is at the midpoint, its speed is 28 m/s and its acceleration is 7 m/s 2 .

Neporo4naja [7]

Answer:

Velocity components

$V_r = -16.28 m/s$

$V_z = -22.8 m/s$

$V_q = 0 m/s$

For Acceleration components;

$a_r = -4.07m/s^2$

$a_z = -5.70m/s^2$

$a_q = 0m/s^2$

Explanation:

We are given:

$Speed v_o = 28 m/s$

$Acceleration a_o= 7 m/s^2$

We first need to find the radial position r of washer in x-y plane.

Therefore

$r = \sqrt{300^2 + 400^2}$

r = 500 mm

To find length along direction OA we have:

$L = \sqrt{500^2 + 700^2}L = 860 mm$

Therefore, the radial and vertical components of velocity will be given as:

$V_r = V_o*cos(Q)$

$V_z = V_o*sin(Q)$

Where Q is the angle between OA and vector r.

Therefore,

$V_r = 28 * \frac{r}{L} = > 28 * \frac{500}{860}$

$V_r = -16.28 m/s$

• $V_z = 28 * \frac{700}{860} = -22.8$

• $V_q = 0 m/s$

The radial and vertical components of acceleration will be:

$a_r = a_o*cos(Q)$

$a_z = a_o*sin(Q)$

Therefore we have:

• $a_r = 7* \frac{500}{860} = -4.07m/s^2$

• $a_z = 7 * \frac{700}{860} = -5.70 m/s^2$

• $a_q = 0 m/s^2$

Note : image is missing, so I attached it

3 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

Use the predicate specifications(x, y): x beats yF (x): x is an (American) football teamQ(x, y): x is quarterback of yL(x,y): x

attashe74 [19]

Answer:

a) ∀y∃x(Q(x, y))

b) (B(Jayhawks, W ildcats)→¬∀y(L(Jayhawks, y)))

c) ∃x(B(Wildcats, x) ∧ B(x, Jayhawks))

Explanation:

a) The statement can be rewritten as "For all football teams, there exists a quarterback" which is written in logical symbols.

b) The statement is an implication and thus have a premise and a conclusion. The premise states "Jayhawks beat the Wildcats" which is translated using B(x, y). The conclusion can be rewritten as "It is not the case that Jayhawks lose to all football teams".

c) The statement is a simple conjunction which can be written as "There exists a team x such that the Wildcats beats x and x beats Jayhawks"

7 0

2 years ago