Ask question

Ask question

All categories

anastassius [24]

3 years ago

7

Lately, you have noticed some repetitive stress in your wrist. Which sign is most likely the cause of that stress and pain?

1 answer:

Cerrena [4.2K]3 years ago

3 0

1, you might have been carrying things that are way too heavy for you.
2, you might have weak tendons.

You might be interested in

Why would a robot process something faster than a human

pantera1 [17]

A robot is a machine. It is often, or almost always, automatic, which means that it is able to perform activities on its own without the aid of external variables, like humans. It moves in the way that it was originally programmed, or designed to act. These actions are described as 'intents' of its own.

8 0

3 years ago

Read 2 more answers

What is the one thing that Zeus loathes the most? What did he do when he caught humans committing this act? What parallels to an

mel-nik [20]

Answer:

ares

Explanation:

He refer ares as the God that he hate the most

8 0

2 years ago

Which one of the following questions about population growth is the only TRUE statement?A) The size of a population can never ex

tatyana61 [14]

Answer:

Explanation:

5

6 0

3 years ago

An industrial plant consists of several 60 Hz single-phase motors with low power factor. The plant absorbs 600 kW with a power f

Gelneren [198K]

Answer:

(a) $Q=332$ $kvar$ and $C=5.66$ $uF$

(b) $pf=0.90$ lagging

Explanation:

Given Data:

$P=600kW$

$V=12.47kV$

$f=60Hz$

$pf_{old} =0.75$

$pf_{new} =0.95$

(a) Find the required kVAR rating of a capacitor

$\alpha _{old}=cos^{-1}(0.75) =41.41$ °

$\alpha _{new}=cos^{-1}(0.95) =18.19$ °

The required compensation reactive power can be found by

$Q=P(tan(\alpha_{old}) - tan(\alpha_{new}))$

$Q=600(tan(41.41) - tan(18.19))$

$Q=332$ $kvar$

The corresponding capacitor value can be found by

$C=Q/2\pi fV^{2}$

$C=332/2*\pi *60*12.47^{2}$

$C=5.66$ $uF$

(b) calculate the resultant supply power factor

First convert the hp into kW

$P_{mech} =250*746=186.5$ $kW$

Find the electrical power (real power) of the motor

$P_{elec} =P_{mech}/n$

where $n$ is the efficiency of the motor

$P_{elec} =186.5/0.80=233.125$ $kW$

The current in the motor is

$I_{m} =(P/\*V*pf)$

The pf of motor is 0.85 Leading

Note that represents the angle in complex notation (polar form)

$I_{m} =(233.125/12.47*0.85)$

$I_{m}=18.694+11.586$ $j$ $A$

Now find the Load current

pf of load is 0.75 lagging (notice the minus sign)

$I_{load} =(600/12.47*0.75)$

$I_{load} =48.115-42.433$ $j$ $A$

Now the supply current is the current flowing in the load plus the current flowing in the motor

$I_{supply} =I_{m} + I_{load}$

$I_{supply}= (18.694+11.586)+(48.115-42.433)$

$I_{supply} =66.809-30.847j$ $A$

or in polar form

$I_{supply} =73.58$ °

Which means that the supply current lags the supply voltage by 24.78

therefore, the supply power factor is

$pf=cos(24.78)=0.90$ lagging

Which makes sense because original power factor was 0.75 then we installed synchronous motor which resulted in improved power factor of 0.90

8 0

3 years ago

Nanotechnology is a scientific area that deals with making or changing things that are incredibly _______________. *

Dafna1 [17]

B tiny nano means small!!

3 0

3 years ago

Read 2 more answers