Answer:
512.5 mJ
Explanation:
Let the two identical charges be q = +35 µC and distance between them be r₁ = 46 cm. A charge q' = +0.50 µC located mid-point between them is at r₂ = 46 cm/2 = 23 cm = 0.23 m.
The electric potential at this point due to the two charges q is thus
V = kq/r₂ + kq/r₂
= 2kq/r₂
= 2 × 9 × 10⁹ Nm²/C² × 35 × 10⁻⁶ C/0.23 m
= 630/0.23 × 10³ V
= 2739.13 × 10³ V
= 2.739 MV
When the charge q' is moved 12 cm closer to either of the two charges, its distance from each charge is now r₃ = r₂ + 12 cm = 23 cm + 12 = 35 cm = 0.35 m and r₄ = r₂ - 12 cm = 23 cm - 12 cm = 11 cm = 0.11 cm.
So, the new electric potential at this point is
V' = kq/r₃ + kq/r₄
= kq(1/r₃ + 1/r₄)
= 9 × 10⁹ Nm²/C² × 35 × 10⁻⁶ C(1/0.35 m + 1/0.11 m)
= 315 × 10³(2.857 + 9.091) V
= 315 × 10³ (11.948) V
= 3763.62 × 10³ V
= 3.764 MV
Now, the work done in moving the charge q' to the point 12 cm from either charge is
W = q'(V' - V)
= 0.5 × 10⁻⁶ C(3.764 MV - 2.739 MV)
= 0.5 × 10⁻⁶ C(1.025 × 10⁶) V
= 0.5125 J
= 512.5 mJ
Yes that would be correct. But if its an essay I'd be a bit more elaborate and give examples.
Answer:
The volume of water evaporated is 199mL
Explanation:
Concentration is calculated with the following formula
where n is the number of moles of solute and V is the volume of the solution (in this case is the same as the solvent volume) in liters.
So we isolate the variable n to know the amount of moles, using the volume given in liters
Now, we isolate the variable V to know the new volume with the new concentration given.
Finally, the volume of water evaporated is the difference between initial and final volume.
That is not middle school grade level.
Answer:
71.8 N
Explanation:
T = Tension force in the strap
W = net work done = 752 J
f = force of friction = 8 N
d = displacement = 15 m
θ = angle between tension force and horizontal displacement = 36 deg
work done by frictional force is given as
W' = - f d
Work done by the tension force is given as
W'' = T d Cos36
Net work done is given as
W = W' + W''
W = T d Cos36 - f d
752 = T (15) Cos36 - (8) (15)
T = 71.8 N
