Which device will allow you to reduce the voltage from 120 vac to vdc in order to charge a cell phone?

Two conductors made of the same material are connected across the same potential difference. Conductor A has three times the dia

Vitek1552 [10]

Answer:

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Explanation:

5 0

3 years ago

An old-fashioned LP record rotates at 33 1/3 RPM

Ksenya-84 [330]

Answer:

Part a) $\frac{5}{9}\ \frac{rev}{sec}$

Part b) $\frac{9}{5}\ \frac{sec}{rev}$

Explanation:

Part a) what is its frequency, in rev/s

we have that

An old-fashioned LP record rotates at 33 1/3 RPM

so

$33\frac{1}{3}\ \frac{rev}{min}$

Convert mixed number to an improper fraction

$33\frac{1}{3}\ \frac{rev}{min}=\frac{33*3+1}{3}=\frac{100}{3}\ \frac{rev}{min}$

Remember that

$1\ min=60\ sec$

Convert rev/min to rev/sec

$\frac{100}{3}\ \frac{rev}{min}=\frac{100}{3}(\frac{1}{60})=\frac{100}{180}\ \frac{rev}{sec}$

Simplify

$\frac{5}{9}\ \frac{rev}{sec}$

Part b) what is it period, in seconds

we know that

The period is the reciprocal of the frequency

therefore

the frequency is

$\frac{9}{5}\ \frac{sec}{rev}$

4 0

3 years ago

Calculate two stars appear to you to have the same brightness. if star a is 7.00 light-years away from you, while star b is 15.0

vagabundo [1.1K]

It is eight times more than the star A.

<h3>What is luminosity and on which it depends?</h3>

The luminosity of an object is a measure of its intrinsic brightness and is defined as the amount of energy the object emits in a fixed time.

luminousity depends upon the two factors are:

1) The star's actual brightness

Some stars are naturally more luminous than others ,so the brightness level from one star to next star is significantly different.

2) The star distance from us

The more distance of an object the dimmer it appears.

Energy emitted = sAT⁴

where s is stefan constant

A is surface area and T is temperature .

to learn more about Luminosity click here brainly.com/question/14140223

#SPJ4

7 0

1 year ago

"An object weighing 10.01 grams is placed in a graduated cylinder containing 3.90 mL of water. If the total volume of the object

Alex73 [517]

Answer:

Density of the object = 1.9399g/mL

Explanation:

Mass of object = 10.01g

Volume of water = 3.90mL

Volume of Object + Water = 9.06mL

Therefore, volume of Object = Volume of Object + Water - Volume of Water

= 9.06mL - 3.90mL

= 5.16mL

Density by definition is the mass per unit volume of a substance.

Density of the object = mass/volume

= 10.01/5.16

= 1.9399g/mL or 1.94kg/m3

8 0

3 years ago

How does the size of arctic foxes ears help to keep them warm in a cold environment

DochEvi [55]

artic foxes have thick white fur to keep them warm and also for camouflage in the snow they have small ears to keep the snow out of their ears so that they can hear better they also have thick fur lining and a thick pad on their feet this stops the paws from getting cold and they have short legs so then the body weight can be spread making it easier for the animal to not sink in the snow in the summer the artic fox turns brown to help make the fox invisible when people are hunting in the long grass

3 0

3 years ago