Pls an answer!<br> fast!!

What is the difference between a direct current and an alternating current?

DerKrebs [107]

<span>In direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically. The voltage in AC circuits also periodically reverses because the current changes direction.</span>

4 0

4 years ago

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12 Write a difference between FPS<br>and CGS unit system of unit.

alexandr1967 [171]

Answer:

CGS means Centimeter Gram Second while FPS means Foot Pounds Second

Explanation:

FPS is the standard used to measurement of length, mass and time. The unit of length is foot.

The time is calculated as the unit of seconds. CGS is the measurement of length, mass and time in units of centimeter, gram and second respectively

8 0

3 years ago

A 70 kg football player running at 3m/s north tackles an 80kg player running at 1.5 m/s south. what is the magnitude and directi

dimulka [17.4K]

It could never actually happen like this, but the question is
looking for you to 'conserve' the momentum.

Momentum of a moving object is (mass) x (velocity).
Like velocity, momentum has a direction.
Momentum is one of those things that's 'conserved'.
That means that momentum can't appear out of nowhere, and
it doesn't disappear. The total after the collision is the same as
the total was before the collision.

Momentum of the skinny player:

   (70 kg) x (3 m/s north) = 210 kg-m/s north.

Momentum of the heavy player:

   (80 kg) x (1.5 m/s south) = 120 kg-m/s south .

Total momentum before the collision is

   (210 kg-m/s north) + (120 kg-m/s south)

   = 90 kg-m/s north .

It has to be the same after the collision.

   (mass) x (velocity) = 90 kg-m/s north.

The mass after the collision is 150 kg, because they get
tangled up and stuck together, and they move together.

(150 kg) x (velocity) = 90 kg-m/s north .

Divide each side
by 150 kg : velocity = (90 kg-m/s north) / (150 kg)

    = (90/150) (kg-m/s / kg north)

   = 0.6 m/s north .

3 0

3 years ago

Star A and Star B have measured stellar parallax of 1.0 arc second and 0.75 arc second, respectively. Which star is closer? How

zhuklara [117]

Answer:

Star A is closer than Star B

Explanation:

As we know that in parallax method of distance measurement the angle subtended by the star when it covers a distance of one Parsec arc length, it is known as parallax angle

Here we can say

$angle = \frac{1 Parsec}{distance}$

so we have

$distance = \frac{1 Parsec}{angle}$

so here we have

angle subtended by Star A = 1 arc sec

angle subtended by star B = 0.75 arc sec

now we have

distance for star A is given as

$d_a = \frac{1 Parsec}{1} = 1 Parsec$

distance of star B is given as

$d_b = \frac{1 Parsec}{0.75} = 1.33 Parsec$

So star A is closer than star B

7 0

4 years ago

A rectangular dam is 101 ft long and 54 ft high. If the water is 35 ft deep, find the force of the water on the dam (the density

blsea [12.9K]

To solve this problem we will begin by finding the pressure through density and average depth. Later we will find the Force, by means of the relation of the pressure and the area.

$P = \rho h$