All categories

2 years ago

Suppose that the voltage is reduced by 10 percent (to 90 V). By what percentage is the power reduced

Physics

1 answer:

skad [1K]2 years ago

3 0

Answer:

percent decrease in power = 20 % .

Explanation:

Power P = v² / R where v is voltage and R is resistance which is constant .

taking log on both sides

log P = 2 log v - log R

differentiating on both sides

dP/P = 2 dv/v

-dP/P x 100 = 2 x -dv/v x 100

percent decrease in power = 2 x percent decrease in v ( voltage )

percent decrease in power = 2 x 10 = 20 %

You might be interested in

. Write the following in the scientific notation of 0.0000002400m

aleksandr82 [10.1K]

Explanation:

<h2>Steps :</h2>

Move decimal from left to right =0 000000240.0
Then count the numbers before decimal and write it like this =240.0x10 power-9
That's all

hope it help

7 0

2 years ago

Why do planets speed up as they get closer to the sun?:

Serggg [28]

Answer:

Explanation:

Gravity is the main reason that make our planets to pull each other

5 0

2 years ago

The pH of coffee is _______ times greater than the pH of pure water.

DENIUS [597]

Answer:

zero times greater

Explanation:

Coffee's pH level is 5

Pure water's pH level is 7

3 0

2 years ago

A 100-kg astronaut is floating in outer space. If the astronaut throws a 2-kilogram wrench at a speed of 10 meters per second, w

sergey [27]

Since Astronaut and wrench system is isolated in the space and there is no external force on it

So here momentum of the system will remain conserved

so here we can say

$m_1v_{1i} + m_2v_{2i} = m_1v_{1f} + m_2v_{2f}$

initially both are at rest

so here plug in all values

$0 = 100 v_{1f} + 2\times 10$

$v_{1f} = -0.20 m/s$

so here the astronaut will move in opposite direction and its speed will be equal to 0.20 m/s

3 0

3 years ago

Free tingsssssssssss

il63 [147K]

Explanation:

yayyy thx u soo muchihuhuhu

5 0

2 years ago

Read 2 more answers