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2 years ago

How many trains have been invented all around the world?

Engineering

1 answer:

umka2103 [35]2 years ago

5 0

Answer:

14,538 trains in the world.

Explanation:

There could be more in the world because they could make more or there could be less??

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A liquid's viscosity increases with increasing temperature. a)-True b)-False

olasank [31]

Answer:

b) False

Explanation:

Viscosity:

Viscosity is a fluid property and comes in the picture when fluid in the motion.In Simple words viscosity is the frictional force offered by fluid between the fluid layer.Viscosity provides a resistant to flow of fluid.

Generally viscosity are of two types

1.Dynamics viscosity

2.Kinematics viscosity

Generally in liquids when temperature of fluid is increases then molecular force between fluid particle goes to decreases.Due to this viscosity of liquids will decrease.

So our option b is right.

7 0

2 years ago

A 4-pole, 3-phase induction motor operates from a supply whose frequency is 60 Hz. calculate: 1- the speed at which the magnetic

DiKsa [7]

Answer:

The answer is below

Explanation:

1) The synchronous speed of an induction motor is the speed of the magnetic field of the stator. It is given by:

$n_s=\frac{120f_s}{p}\\ Where\ p\ is \ the \ number\ of\ machine\ pole, f_s\ is\ the\ supply \ frequency\\and\ n_s\ is \ the \ synchronous\ speed(speed \ of\ stator\ magnetic \ field)\\Given: f_s=60\ Hz, p=4. Therefore\\\\n_s=\frac{120*60}{4}=1800\ rpm$

2) The speed of the rotor is the motor speed. The slip is given by:

$Slip=\frac{n_s-n_m}{n_s}. \\ n_m\ is\ the \ motor\ speed(rotor\ speed)\\Slip = 0.05, n_s= 1800\ rpm\\ \\0.05=\frac{1800-n_m}{1800}\\\\ 1800-n_m=90\\\\n_m=1800-90=1710\ rpm$

3) The frequency of the rotor is given as:

$f_r=slip*f_s\\f_r=0.04*60=2.4\ Hz$

4) At standstill, the speed of the motor is 0, therefore the slip is 1.

The frequency of the rotor is given as:

$f_r=slip*f_s\\f_r=1*60=60\ Hz$

6 0

3 years ago

What are the general rules for press fit allowances

Keith_Richards [23]

Explanation:

As a general rule of thumb, the large the diameter of a bearing, bushing or pin, the larger the tolerance range,” Brieschke points out. “The inverse is true for smaller-diameter pieces.”

Mike Brieschke, vice president of sales at Aries Engineering, says a 0.25-inch-diameter metal dowel that is press-fit into a mild steel hole usually has an interference of ±0.0015 inch. Parts in noncritical assemblies tend to have looser tolerances

please rate brainliest if helps and follow

4 0

1 year ago

2. Explain advantages and disadvantages of computer.<br>Each five.

Salsk061 [2.6K]

Answer:

Hope it helps...

Explanation:

-the main advantages and benefits you'll get from using a computer.

Increase your productivity. ...

Connects you to the Internet. ...

Can store vast amounts of information and reduce waste. ...

Helps sort, organize, and search through information. ...

Get a better understanding of data. ...

Keeps you connected.

the disadvantages to using a computer and what type of problems you may personally encounter.

Carpal tunnel and eye strain. ...

Too much sitting. ...

Short attention span and too much multitasking. ...

Can limit learning and create a dependency. ...

Potential of loss of privacy. ...

Time sink and lots of distractions.

PLEASE THANK MY ANSWER

3 0

3 years ago

Please help i give brainliest

Mazyrski [523]

Answer:

A mock-up

Explanation:

It is made of cheap and easy to access parts.

5 0

2 years ago