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3 years ago

What did the ancient Greeks use simple machines for?

2 answers:

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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Oleg is using a multimeter to test the circuit branch you just installed. After turning off the current to the circuit at the se

irakobra [83]

Answer:

Option D, Ground Wire

Explanation:

Oleg is a mustimeter or multi tester or a basic voltage tester which is used to test the ground. The main purpose of the tester is to ensure that the outlet is connected to the ground of the circuit, thereby ensuring its proper functioning.

Hence, option D is correct

7 0

2 years ago

Problem 3: Soil Classification using the AASHTO and USCS Systems

nataly862011 [7]

<u>Solution:</u>

$Given\\ $\quad W=3000 Ib , \quad m=\frac{W}{g}=\frac{3000}{322} \ slug =93.1677 slug$\\K_{e q}=2160 lbs / wp =2100 \frac{ lbs }{10} \frac{ x 12}{1 ft }=(2160 \times 12) lb / ft$$$

a) The natural frequency

$\begin{aligned}&\left(\omega_{n}\right)=\sqrt{\frac{K_{e q}}{m}}\\&=\sqrt{\frac{2160 \times 12}{93.1677}}\\&\omega_{n}=16.68 \text { rad } | s\\&\omega_{n}=\frac{2 \pi}{T}\\&16.68=\frac{2 \pi}{T}\\&T=0.3767 s\end{aligned}$

$Given, $t=10 s , \quad y(t)=6 in = A$\\$y(t)=A \cos \left(\omega_{n} t+\phi\right) \rightarrow 0$\\$6=6 \cos (16.68 \times 10+\phi)$\\$1=\cos (166.8+\phi)$\\$166.8+\phi=0$\\\phi=-166.8\)\\At $t=0, \quad y(0)=6 \cos (16.68 \times 0-166.8)$ {y(0)}=-5.74 in$

5 0

2 years ago

A heat engine is coupled with a dynamometer. The length of the load arm is 900 mm. The spring balance reading is 16. Applied wei

miss Akunina [59]

Answer:

P = 80.922 KW

Explanation:

Given data;

Length of load arm is 900 mm = 0.9 m

Spring balanced read 16 N

Applied weight is 500 N

Rotational speed is 1774 rpm

we know that power is given as

$P = T\times \omega$

T Torque = (w -s) L = (500 - 16)0.9 = 435.6 Nm

$\omega$ angular speed $=\frac{2 \pi N}{60}$

Therefore Power is

$P =\frac{435.6 \time 2 \pi \times 1774}{60} = 80922.65 watt$

P = 80.922 KW

4 0

3 years ago

What is flow energy? Do fluids at rest possess any flow energy?

anzhelika [568]

Answer:

Flow energy is defined as, flow energy is the energy needed to push fluids into control volume and it is the amount of work done required to push the entire fluid. It is also known as flow work. Flow energy is not the fundamental quantities like potential and kinetic energy.

Fluid at state of rest do not possess any flow energy. It is mostly converted into internal energy as, rising in the fluid temperature.

8 0

2 years ago

How are speed and acceleration related

erica [24]

R = distance

dr/dt speed or with a direction, velocity

d(dr/dt)/dt = the time derivative of the velocity is called acceleration.

Speed is a scalar. Acceleration is a vector.

6 0

2 years ago

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