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3 years ago

The voltage of electricity traveling away from a power plant is very high. How high may it be? Why is the voltage so high?

1 answer:

8 0

- The voltage travelling away from a power plant through transmission lines is very high, and it is typically of hundreds of kilovolts (typical values are between 138 kV and 765 kV).

- The main reason to use these high values of voltage is to reduce power dissipation.
In fact, the cables that are used to transmit electricity have a certain resistance R which is fixed. The power generated from the power plant and that should be transmitted through the lines is P, and it is also fixed.
The power dissipated through the cables is calculated as
$P_{diss}=I^2 R = (\frac{P}{V} )^2 R$
where I is the current and V the voltage.
As it can be seen, using higher voltages reduce the amount of power dissipated through the lines (while using higher currents will have the opposite effect).

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two negative charges that are both -3.0 C push each other apart with a force of 19.2 N how far apart are the charges

Hoochie [10]

The electrostatic force between two charges q1 and q2 is given by
$F=k_e \frac{q_1 q_2}{r^2}$
where $k_e =8.99 \cdot 10^9 N m^2 C^{-2}$ is the Coulomb's constant and r is the distance between the two charges.

If we use F=19.2 N and q1=q2=-3.0 C, we can find the value of r, the distance between the two charges by re-arranging the previous formula:
$r= \sqrt{k_e \frac{q_1 q_2}{F} }= \sqrt{ 8.99 \cdot 10^9 N m^2 C^{-2} \frac{(-3.0C)^2}{19.2 N} } =6.49 \cdot 10^4 m=64.9 km$

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3 years ago

What happens when the elevator is in free-fall, that is, what is the value for FN and what is the sensation experienced by the p

Komok [63]

Answer:

Weightlessness

Explanation:

When the elevator is in free fall, this can only occur when the cord of the elevator breaks.

The acceleration of the elevator will be equal to the acceleration due to gravity. That is:

a = g

Then, the body will experience what we called WEIGHTLESSNESS

Where the normal reaction N of the person will tend to zero. That is

N = 0

The value of FN < 0 because the person inside the lift will experience weightlessness.

7 0

2 years ago

If you want to increase the gravitational force between two objects; would you rather double the mass of one object or halve the

Step2247 [10]

To solve this problem we will apply the concepts related to the Force of gravity from Newtonian theory for which it is necessary to

$F = \frac{GMm}{R^2}$

Where,

G = Gravitational universal constant

M = Mass of Earth

m = mass of Object

x = Distance between center of mass of the objects.

From this equation we can observe that the Force is inversely proportional to the squared distance between the two objects. The greater the distance, the lower the force of gravity and vice versa.

$F \propto \frac{1}{R^2}$

If you want to increase the force of gravity, you need to reduce the distance of the two. Therefore the correct option is B. Talk to the distance between them.

5 0

3 years ago

A steel block has a volume of 0.08 m³ and a density of 7,840 kg/m³. What is the force of gravity acting on the block (the weight

Alex17521 [72]

Force of gravity =mass*graviational acceleration
gravitational acceleration=g=9.81
mass=Density*Volume=.08*7840
force of gravity= .08*7840*9.81
gg

5 0

2 years ago

When you used the energy in our body to pull the rubber band, it was transformed into elastic potential energy. We know that ene

GuDViN [60]

Answer:

Converted to heat energy

Explanation:

Some of the elastic potential energy is transformed into heat energy. When we stretch a rubber band, it is often observed that the rubber becomes warmer after the stretch and even during the stretch.

Some energy in the band initially at rest will be converted into elastic potential energy and heat energy as it is stretched .

The heat energy is not usually accounted for since the major concern most times is the elastic energy.
In this process, heat energy becomes a waste energy.
By deducing the efficiency, we would find that this transformation is not efficient as predicted by one of the laws of thermodynamics.

3 0

3 years ago