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Romashka [77]
3 years ago
15

What did the ancient Greeks use simple machines for?

Engineering
2 answers:
nalin [4]3 years ago
6 0
Native Americans who used spears to hunt were using wedges. In the third century BC, the Greek scientist Archimedes invented a way to lift water, called the Archimedes screw. It was used to water crops and to move water out of ships.
11Alexandr11 [23.1K]3 years ago
4 0

Answer:The idea of a simple machine originated with the Greek philosopher Archimedes around the 3rd century BC, who studied the Archimedean simple machines: lever, pulley, and screw. He discovered the principle of mechanical advantage in the lever.

Explanation:

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A binary liquid system exhibits LLE at 25°C. Determine from each of the following sets of miscibility data estimates for paramet
Phoenix [80]

Answer:

(a) - A12 = A21 = 2.747

(b) - A12 = 2.148; A21 = 2.781

(c)-  A12 = 2.781; A21 = 2.148

Explanation:

(a) - x1(a) = 0.1 |  x2(a) = 0.9 | x1(b) = 0.9 | x2(b) = 0.1

LLE equations:

  • x1(a)*γ1(a) = x1(b)γ1(b)

        x2(a)*γ2(a) = x2(b)γ2(b)

  • A12 = A21 = 2.747

(b) -  x1(a) = 0.2 |  x2(a) = 0.8 | x1(b) = 0.9 | x2(b) = 0.1

LLE equations:

  • x1(a)*γ1(a) = x1(b)γ1(b)

        x2(a)*γ2(a) = x2(b)γ2(b)

  • A12 = 2.148; A21 = 2.781

(c) -  x1(a) = 0.1 |  x2(a) = 0.9 | x1(b) = 0.8 | x2(b) = 0.2

LLE equations:

  • x1(a)*γ1(a) = x1(b)γ1(b)

        x2(a)*γ2(a) = x2(b)γ2(b)

  • A12 = 2.781; A21 = 2.148
7 0
3 years ago
An aircraft component is fabricated from an aluminum alloy that has a plane strain fracture toughness of 30 . It has been determ
UNO [17]

Answer:

fracture will occur since ( 31.8 Mpa√m ) is greater than the K_{Ic of the material ( 30 Mpa√m )

Explanation:

Given the data in the question;

To determine whether the aircraft component will fracture, given a fracture toughness of 30 Mpa√m, stress level of 355 and maximum internal crack length of 1.39 mm.

On a similar component, it has been said that fracture results at a stress of 237 MPa when the maximum (or critical) internal crack length is 2.78 mm.

so we first of all solve for the parameter Y in the condition where fracture occurred.

K_{Ic = 30 Mpa√m

σ = 237 MPa

2α = 2.78 mm = 2.78 × 10⁻³ m  

so

Y = K_{Ic / σ√πα

we substitute

Y = (30 Mpa√m) / (237 MPa)√(π(2.78 × 10⁻³ m / 2 ) )

Y =  (30 Mpa) / (237)( 0.06608187 )

Y = 30 / 15.6614

Y = 1.9155

Next we solve for Yσ√πα for the second case;

σ = 355 Mpa, 2α = 1.39 mm = 1.39 × 10⁻³ m

so

Yσ√πα = 1.9155 × 355 Mpa × √( π × (1.39 × 10⁻³ m / 2) )

= 1.9155 × 355 × 0.0467269

= 31.8 Mpa√m

so

( 31.8 Mpa√m ) > K_{Ic ( 30 Mpa√m )

Therefore, fracture will occur since ( 31.8 Mpa√m ) is greater than the K_{Ic of the material ( 30 Mpa√m )

4 0
2 years ago
Component(s) that only allow(s) electrons to flow in one direction. Mark all that apply
Korolek [52]

Answer:

A,D, and E

Explanation:

6 0
2 years ago
Select four items that an industrial engineer must obtain in order to practice in the field.
alex41 [277]

Answer:

Professional engineering license

Bachelor's degree

Computer science classes

job recommendations

3 0
1 year ago
Read 2 more answers
Two sites are being considered for wind power generation. On the first site, the wind blows steadily at 7 m/s for 3000 hours per
kirill [66]

Solution :

Given :

$V_1 = 7 \ m/s$

Operation time, $T_1$ = 3000 hours per year

$V_2 = 10 \ m/s$

Operation time, $T_2$ = 2000 hours per year

The density, ρ = $1.25 \ kg/m^3$

The wind blows steadily. So, the K.E. = $(0.5 \dot{m} V^2)$

                                                             $= \dot{m} \times 0.5 V^2$

The power generation is the time rate of the kinetic energy which can be calculated as follows:

Power = $\Delta \ \dot{K.E.} = \dot{m} \frac{V^2}{2}$

Regarding that $\dot m \propto V$. Then,

Power $ \propto V^3$ → Power = constant x $V^3$

Since, $\rho_a$ is constant for both the sites and the area is the same as same winf turbine is used.

For the first site,

Power, $P_1= \text{const.} \times V_1^3$

            $P_1 = \text{const.} \times 343 \ W$

For the second site,

Power, $P_2 = \text{const.} \times V_2^3 \ W$

           $P_2 = \text{const.} \times 1000 \ W$

5 0
2 years ago
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