Three identical particles of mass m=5 grams and charge q=3.4 microCoulombs are a

Question

Three identical particles of mass m=5 grams and charge q=3.4 microCoulombs are assembled from infinity to form an equilateral triangle with sides of length d=8.9 cm as shown in the figure. Let W be the work required to assemble the triangle of charges by the following method. Charge A is first nailed down. Charge B is then moved from infinity and nailed down at a distance d from Charge A. Finally Charge C is moved in from infinity and nailed down at the apex of the triangle. After the triangle is assembled, the nail holding Charge C is removed and it flies off to infinity -- ultimately reaching a speed of vC. Charge A and B are still nailed down. Find vC in meters/sec.

Explanation / Answer

when they are placed at corners of equililateral triangle,

electric potential energy of the system,

U1 = 3*k*q^2/d = 2.38 J

when charge C moves to infinite distance,

electric potential energy of the system,

U2 = k*q^2/d = 0.793 J

workdone = -(U2 - U1) = 1.587 J

0.5*m*vc^2 = 1.58 J

0.5*0.005*vc^2 = 1.587

vc = sqrt(1.587*2/0.005)

vc = 25.2 m/s

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.