Answer:
It is easier to scale the voltage of AC from high to low and low to high than with DC
Explanation:
typically power is used far away from the place where it's generated so to ensure that transmission losses( copper losses) are minimized voltage has to be stepped up during transmission..but due to the fact that most house hold equipment requires low voltage levels it has to be stepped down once it reaches a household/ domestic load...it's easier to do this for Ac than for DC.
Answer:
q₃ = -4.81 nC
Explanation:
We can use the Gauss Law here:
∅ = q/∈₀
where,
∅ = Net Flux = - 216 N.m²/C
q = total charge enclosed inside sphere = ?
∈₀ = permittivity of free space = 8.85 x 10⁻¹² C/N.m²
Therefore,
- 216 N.m²/C = q / 8.85 x 10⁻¹² C²/N.m²
q = (-216 N.m²/C)(8.85 x 10⁻¹² C²/N.m²)
q = - 1.91 nC
So, the total charge will be sum of all three charges:
q = q₁ + q₂ + q₃
- 1.91 nC = 1.74 nC + 1.16 nC + q₃
q₃ = - 1.91 nC - 1.74 nC - 1.16 nC
<u>q₃ = -4.81 nC</u>
Answer:
The handrails must be approximately 10.63 meters long
Explanation:
The given parameters are;
The height of the bleachers, h = 8 m
The depth of the bleachers, d = 7 m
The length of the hand rails to go along the bleachers from bottom to top is given by Pythagoras' Theorem as follows;
The length of the hand rail = √(d² + h²)
∴ The length of the hand rail = √(7² + 8²) = √113 ≈ 10.63
In order for the handrails to go along the bleachers from top to bottom, they must be approximately 10.63 meters long.
This next statement is a big deal. It should be up on a board, surrounded
by flashing red and yellow lights, and hung on the wall of every Science
classroom. Although we never see it in our daily lives, it's fundamental to
the workings of the universe, and it's also Newton's first law of motion:
<em>Without friction, it doesn't take <u>ANY</u> force to keep a moving object
moving. </em><em>Force is only required to <u>change</u> the object's speed, or to
<u>change</u> the direction </em><em>in which it's moving.</em>
The answer to the question is: On a level road, and neglecting any friction,
the engine doesn't have to supply ANY force to keep the car going at the
same speed.
