Man start to moves from point A (Initial Point) to Point B (Final Point) in a given
1 answer:
You might be interested in
Answer:
W = 0×(kq2L)
Explanation:
We know that the work to assemble a charge configuration of two charges a distance r from each other is simply W = kq2/r
If we want to assemble three charges A, B, and C. It's necessary to consider the distances between them
WABC = kq2/(rAB + rAC + rBC)
So, to assemble four charges A, B, C, & D....
WABCD = kq2/(rAB + rAC + rAD + rBC + rBD + rCD)
Considering a square charge configuration with sides L, such as in figure attached A, B, & C are positive & D is negative
rAB = L
rAC = L√2
rAD = L (-)
rBC = L
rBD = L√2 (-)
rCD = L (-)
⇒ W = kq2/(L + L√2 + (-L) + L + (-L√2) + (-L)
⇒ ∴ W = 0 × (kq2/L)
This way, working through each option...
(a)
The positive charges are equidistant from each other at a distance of L.
rAB = L
rAC = L
rAD = ½L⋅sin(60) (-)
rBC = L
rBD = ½L⋅sin(60) (-)
rCD = ½L⋅sin(60) (-)
Wa = kq2/(3L - (3/2)L⋅(0.866))
⇒ ∴ Wa = (1/1.7) × (kq2/L) = (0.5879)× (kq2/L)
(b)
rAB = L
rAC = 2L
rAD = 3L (-)
rBC = L
rBD = 2L (-)
rCD = L (-)
Wb = kq2/(4L - 6L)
⇒ ∴ Wb = (-1/2) × (kq2/L) = (-0.5)× (kq2/L)
(c)
The factor doesn't matter, so Wc = 0 × (kq2/L)
In this case, the greater work is actually the less work. Therefore, the positive work represents the amount of work the system actually exhibits, that we don't have to do. If there is negative work, we have to make up that work in order to place the charges as desired.
This way, charge configuration (a) requires the least amount of work.
66.7 Watts
Explanation:
Let ohms,
ohms and
ohms. Since
and
are in parallel, their combined resistance
is given by
or
The total current flowing through the circuit <em>I</em> is given
where
Therefore, the total current through the circuit is
In order to find the voltage drop across the 6-ohm resistor, we first need to find the voltage drop across the 1-ohm resistor :
This means that voltage drop across the 6-ohm resistor is 20 V. The power dissipated <em>P</em> by the 6-ohm resitor is given by