Answer:
A) the current in AC electricity varies in magnitude and direction.
C) the voltage in AC electricity varies in magnitude and direction.
Explanation:
In DC current and voltage the direction of current will not change with time and it always remains the same.
So here in DC voltage and DC current the magnitude may change with time but the direction will always remain same
While in AC voltage and AC current the direction of AC will change with time
periodically.
So here magnitude and direction both will change in AC current and AC voltage.
so the correct answer is
A) the current in AC electricity varies in magnitude and direction.
C) the voltage in AC electricity varies in magnitude and direction.
Explanation:
average speed = total distance travelled / total time travelled
time to travel the first 6km: 6 / 50 = 3/25 (h)
time to travel the next 6km: 6 / 90 = 1/15 (h)
[I think there's problem in the question 'cause 900km/h sounds impossible for normal person to travel in normal condition]
The total time: 3/25 + 1/15 = 14/75 (h)
Average speed over the 12 km drive will be:

Answer:The specific heat capacity of water is 4,200 joules per kilogram per degree Celsius (J/kg°C). This means that it takes 4,200 J to raise the temperature of 1 kg of water by 1°C.
Explanation:
Answer:
the final speed of object A changed by a factor of
= 0.58
the final speed of object B changed by a factor of
= 1.29
Explanation:
Given;
kinetic energy of object A, = 27 J
let the mass of object A = 
then, the mass of object B = 
work done on object A = -18 J
work done on object B = -18 J
let
be the initial speed
let
be the final speed
For object A;


Thus, the final speed of object A changed by a factor of
= 0.58
To obtain the change in the final speed of object B, apply the following equations.


Thus, the final speed of object B changed by a factor of
= 1.29
"Acceleration" does NOT mean speeding up. It also doesn't mean
slowing down. Acceleration means ANY change in the speed
OR DIRECTION of motion.
The only kind of motion that's NOT accelerated is motion at a steady
speed AND in a straight line.
Even when your speed is steady, you're accelerating if your direction
is changing.
A few examples:
(no speeds are changing):
-- driving on a curved road, or turning a corner
-- going around a curve on a skateboard, a bike, or a Segway
-- running on a quarter-mile track
-- an Indy car cruising a practice lap around the track
-- water spinning, getting ready to go down the drain
-- any point on the blade of a fan
-- the little ball going around the inside of a Roulette wheel
-- the Moon in its orbit around the Earth
-- the Earth in its orbit around the sun