AC reverses the current in periods, and the current flows in 2 directions.
DC only flows in one direction and is constant.

AC is typically used to transfer power over long distances from a generator to your home, stepping it up after it's generated to send it over the distance, then stepping it back down so that it is usable in your home.

DC is used typically inside of devices, as it sends a certain amount of electricity through the wires.

Nicolas Tesla, was ripped off by Edison to replace his DC stations with AC instead. ^^

4 0

3 years ago

Mark Watney begins his day 15 km West and 25 km North of his Mars Habitat. a. Set up a co-ordinate system (draw labeled axis and

Goryan [66]

Answer:

a, b) part a and b on diagram attached

c) sf = -35 i + 20 j

35 km West and 20 km North

Explanation:

For part a and b refer to the attached co-ordinate system:

Note: unit vector i is in West/East direction and unit vector j is in North/South direction.

si = -15 i + 25 j

sf-si = -20 i - 5 j

Hence,

Mark relative position from habitat sf = si + sf/i

sf = ( -15 i + 25 j ) + ( -20 i - 5 j )

sf = -35 i + 20 j

35 km West and 20 km North

4 0

3 years ago

An enemy spaceship is moving toward your starfighter with a speed, as measured in your frame, of 0.400c. The enemy ship fires a

kvasek [131]

Answer:

0.859375c

31.03 seconds

Explanation:

v' = Velocity of my ship = 0.4 c

u = Velocity of rocket = 0.7 c

c = Speed of light = $3\times 10^8\ m/s$

s = Distance between my ship and enemy ship = $8\times 10^6\ km$

Relativistic addition of speed is given by

$v=\dfrac{v'+u}{1+\dfrac{uv'}{c^2}}\\\Rightarrow v=\dfrac{0.7+0.4}{1+\dfrac{0.7c\times 0.4c}{c^2}}\\\Rightarrow v=0.859375\ c$

The speed of the missile is 0.859375c

Time is given by

$t=\dfrac{s}{v}\\\Rightarrow t=\dfrac{8\times 10^9}{0.859375\times 3\times 10^8}\\\Rightarrow t=31.03\ s$

It will take 31.03 seconds to reach me.

6 0

3 years ago