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3 years ago

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

Physics

1 answer:

Darina [25.2K]3 years ago

6 0

It should be 4. An alternator

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Consider the minute hand on a clock. (a) Compute the frequency of its motion in cycles per second. State your answer to three si

kicyunya [14]

Answer:

(a)0.0002778

(b) $1.16\times10^{-5}$

Explanation:

(a) The minute hand has a period of 60 minutes ( or 60 * 60 = 3600 seconds) for 1 circle. Its frequency per second would be

1 / 3600 = 0.0002778

(b) The hour hand has a period of 24 hours ( or 24*60 * 60 = 86400

seconds) for 1 circle. Its frequency per second would be

$1 / 86400 = 1.16\times10^{-5}$

5 0

3 years ago

When the dry-bulb reading of a thermometer is 20°C and the wet-bulb reading is 11°C, the relative humidity is approximately

8090 [49]

Answer:

You need to use charts or a calculator to get 56%

Explanation:

3 0

3 years ago

Productivity increases when A. inputs increase while outputs remain the same. B. inputs decrease while outputs remain the same.

Blizzard [7]

Answer: Productivity increases when inputs and outputs increase proportionately.

Explanation:

Productivity increases when inputs and outputs increase proportionately. Input has to be directly proportional to output to be productive. This means increase in input to a system must leads to drastic increase in the output. When the output is not balanced with the amount of input, it leads to unproductivity.

Being productive can be business wise or in terms if personal growth and development.

3 0

3 years ago

According to the principal of wave refraction, when light from the atmosphere enters a medium of greater density at an oblique a

Hoochie [10]

Answer:

d. velocity slows down and angle changes

Explanation:

6 0

3 years ago

A sealed test tube traps 25.0 cm3 of air at a pressure of 1.00 atm and temperature of 18°C. The test tube’s stopper has a diamet

puteri [66]

Answer:

180° C

Explanation:

First we start by finding the area of the stopper.

A = πd²/4, where d = 1.5 cm = 0.015 m

A = 3.142 * 0.015² * ¼

A = 1.767*10^-4 m²

Next we find the force on the stopper

F = (P - P•)A, where

F = 10 N

P = pressure inside the tube,

P• = 1 atm

10 = (P - 101325) * 1.767*10^-4

P - 101325 = 10/1.767*10^-4

P - 101325 = 56593

P = 56593 + 101325

P = 157918 Pascal

Now, remember, in an ideal gas,

P1V1/T1 = P2V2/T2, where V is constant, then we have

P1/T1 = P2/T2, and when we substitute the values, we have

101325/(273 + 18) = 157918/ T2

101325/291 = 157918/ T2

T2 = (157918 * 291)/101325

T2 = 453 K

T2 = 453 - 273 = 180° C

3 0

3 years ago