Which of the following is not a simple machine.

Engineering

1 answer:

Anastaziya [24]4 years ago

5 0

Answer:

elevator

Explanation:

the simple machines are inclined plane, lever, wedge, wheel and axle, pulley, and screw. Although an elevator has many of these in it, an elevator is not a simple machine. they are quite complex as illustrated below by Randal Munroe.

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The two basic categories of electrical switches are manual and ??

Ganezh [65]

Answer:

are Manual and Automatic

4 0

3 years ago

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Three parallel three-phase loads are supplied from a 480V (line-line RMS), 60 Hz three-phase supply. The loads are as follows: L

Travka [436]

Answer:

The total system active power P = P_1 + P_2 + P_3 = 34.91 KW

Explanation:

Load 1: Active power P_1 = 20 HP = 14.91kW;

Reactive power $Q1 = P tan(\phi)$

$= 14.91\times tan(cos^{-}0.8) = 11.18 kvar
$

Load 2: Active power P_2 = 20 kW;

Reactive power Q2 = 0 since the load is purely resistive.

Load 3: Active power $P_3$ = 0 due to purely capacitiveload

Reactive power $Q_3$ = -20 Var

a) since all three loads are connected in parallel therefore

The total system active power P = P_1 + P_2 + P_3 = 34.91 KW

Total system reactive power Q = Q_1 + Q_2 + Q_3 = 11.18 + 0 -20 = -8.82 kVar

Since Q = 0, the power factor is unity.

Supply current per phase is given by

$I = \frac{P}{\sqrt{3}V_{L}}$

$= \frac{34910}{\sqrt{3}\times 480} = 41.99 A$

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3 years ago

Consider steady heat transfer through the wall of a room in winter. The convection heat transfer coefficient at the outer surfac

AveGali [126]

The heat transfer which is in steady state, the heat transfer rate to the wall is equal to the wall.

<u>Explanation:</u>

The convection transfer of heat to the wall is

$Q=h A\left(T_{s}-T_{f}\right)$

Here, $T_{S}$ is the temperature of solid surface, $T_{f}$ is the temperature of moving fluid stream which is adjacent of solid surface, h is the heat transfer coefficient.
The coefficient of convection heat transfers outer surface contains 3 times to the inner surface which experience smaller drop of temperature for 3 times that compares to inner surface.
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