Item 6 You have a lightweight spring whose unstretched length is 4.0 cm. First,

Question

Item 6 You have a lightweight spring whose unstretched length is 4.0 cm. First, you attach one end of the spring to the ceiling and hang a 1.2 g mass from it. This stretches the spring to a length of 5.2 cm . You then attach two small plastic beads to the opposite ends of the spring, lay the spring on a frictionless table, and give each plastic bead the same charge. This stretches the spring to a length of 4.4 cm. Part A What is the magnitude of the charge (in nC) on each bead? Express your answer using two significant figures.

Explanation / Answer

Let K is the spring constant.
when the spring suspended by a body vertically,

Apply, Hook's law

F = k*y (here y is exetension of the spring)

m*g = k*y

==> k = m*g/y

= 1.2*10^-3*9.8/(1.2*10^-2)

= 0.98 N/m

Let the charge on each bead is q.

when the spring is placed on table.

Force between two charges particle,

F = k*x

ke*q^2/(L+x)^2 = k*x (here L is the unstrethced length of the spring)

q = (L+x)*sqrt(k*x/ke)

= (0.04 + 0.004)*sqrt(0.98*0.004/(9*10^9))

= 2.9*10^-8 C

= 29 nC <<<<<<-------------------Answer

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

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