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3 years ago

What are the advantages to a quality saw?

1 answer:

7 0

Ans: A quality handsaw makes jobs such as crosscutting moldings, cleaning out dovetails and flush cutting dowels and pegs faster, cleaner and safer. There are myriad different types and sizes of blades for working with wood and other materials.

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2. A mild steel wire of radius 0.5mm and length 3m is stretched by a force of 49 N. Calculate:

damaskus [11]

I don’t know how to answer :’(

6 0

2 years ago

An ideal Otto cycle has a compression ratio of 9.2 and uses air as the working fluid. At the beginning of the compression proces

Allushta [10]

Answer:

(a) The amount of heat transferred to the air, $q_{out}$ is 215.5077 kJ/kg

(b) The net work output, $W_{net}$ , is 308.07 kJ/kg

(d) The Mean Effective Pressure, MEP, is 393.209 kPa

Explanation:

(a) The assumptions made are;

$c_p$ = 1.005 kJ/(kg·K), $c_v$ = 0.718 kJ/(kg·K), R = 0.287 kJ/(kg·K),

Process 1 to 2 is isentropic compression, therefore;

$T_{2}= T_{1}\left (\dfrac{v_{1}}{v_{2}} \right )^{k-1} = 300.15\times 9.2^{0.4} = 729.21 \, K$

From;

$\dfrac{p_{1}\times v_{1}}{T_{1}} = \dfrac{p_{2}\times v_{2}}{T_{2} }$

We have;

$p_{2} = \dfrac{p_{1}\times v_{1}\times T_{2}}{T_{1} \times v_{2}} = \dfrac{98\times 9.2\times 729.21}{300.15 } = 2190.43 \, kPa$

Process 2 to 3 is reversible constant volume heating, therefore;

$\dfrac{p_3}{T_3} =\dfrac{p_2}{T_2}$

p₃ = 2 × p₂ = 2 × 2190.43 = 4380.86 kPa

$T_3 = \dfrac{p_3 \times T_2}{p_2} =\dfrac{4380.86 \times 729.21}{2190.43} = 1458.42 \, K$

Process 3 to 4 is isentropic expansion, therefore;

$T_{3}= T_{4}\left (\dfrac{v_{4}}{v_{3}} \right )^{k-1}$

$1458.42= T_{4} \times \left (9.2 \right )^{0.4}$

$T_4 = \dfrac{1458.42}{(9.2)^{0.4}} = 600.3 \, K$

$q_{out} = m \times c_v \times (T_4 - T_1) = 0.718 \times (600.3 - 300.15) = 215.5077 \, kJ/kg$

The amount of heat transferred to the air, $q_{out}$ = 215.5077 kJ/kg

(b) The net work output, $W_{net}$ , is found as follows;

$W_{net} = q_{in} - q_{out}$

$q_{in} = m \times c_v \times (T_3 - T_2) = 0.718 \times (1458.42 - 729.21) = 523.574 \, kJ/kg$

$\therefore W_{net} = 523.574 - 215.5077 = 308.07 \, kJ/kg$

$\eta_{th} = \dfrac{W_{net}}{q_{in}} \times 100= \dfrac{308.07}{523.574} \times 100= 58.8\%$

(d) From the general gas equation, we have;

$V_{1} = \dfrac{m\times R\times T_{1}}{p_{1}} = \dfrac{1\times 0.287\times 300.15}{98} =0.897\, m^{3}/kg$

The Mean Effective Pressure, MEP, is given as follows;

$MEP =\dfrac{W_{net}}{V_1 - V_2} = \dfrac{W_{net}}{V_1 \times (1- 1/r)}= \dfrac{308.07}{0.897\times (1- 1/9.2)} = 393.209 \, kPa$

The Mean Effective Pressure, MEP = 393.209 kPa.

3 0

3 years ago

An artist is creating a gigantic mobile using old cars. On one end of the mobile, a 2100 lb Plymoth is suspended 30 feet from th

ozzi

Answer:

c 45 feet from the fulcrum

Explanation:

The moment at the fulcrum must be the same for each car. If the distance is d, then the artist must have ...

(2100 lb)(30 ft) = (1400 lb)(d)

2100·30/1400 ft = d = 45 ft

The Volkswagen should be 45 ft from the fulcrum.

7 0

3 years ago

Read 2 more answers

Consider a solid circular shaft subjected to bending and torsion so that the state of stress of interest involves only a normal

Alex17521 [72]

Answer:

The detailed explanation of answer is given in attached file.

Explanation:

7 0

3 years ago

Convert 850 nm wavelength into frequency, eV, wavenumber, joules and ergs.

BabaBlast [244]

Answer:

Frequency = 3.5294×10¹⁴ s⁻¹

Wavenumber = 1.1765×10⁶ m⁻¹

Energy = 2.3365x 10⁻¹⁹ J , 1.4579 eV , 2.3365x 10⁻¹² erg

Explanation:

Given the wavelength = 850 nm

1 nm = 10⁻⁹ m

So, wavelength is 850×10⁻⁹ m

The relation between frequency and wavelength is shown below as:

c = frequency × Wavelength

Where, c is the speed of light having value = 3×10⁸ m/s

So, Frequency is:

Frequency = c / Wavelength

$Frequency=\frac {3\times 10^8\ m/s}{850\times 10^{-9}\ m}$

Frequency = 3.5294×10¹⁴ s⁻¹

Wavenumber is the reciprocal of wavelength.

So,

Wavenumber = 1 / Wavelength = 1 / 850×10⁻⁹ m

Wavenumber = 1.1765×10⁶ m⁻¹

Also,

$Energy=h\times frequency$

where, h is Plank's constant having value as 6.62x 10⁻³⁴ J.s

So,

Energy = 6.62x 10⁻³⁴ J.s × 3.5294×10¹⁴ s⁻¹

Energy = 2.3365x 10⁻¹⁹ J

Also,

1 J = 6.24×10¹⁸ eV

So,

Energy = 2.3365x 10⁻¹⁹ × 6.24×10¹⁸ eV

Energy = 1.4579 eV

Also,

1 J = 10⁷ erg

So,

Energy = 2.3365x 10⁻¹⁹ × 10⁷ erg

Energy = 2.3365x 10⁻¹² erg

8 0

3 years ago