A 2.75-gram air inflated balloon is given an excess negative charge, q1 = -4.00

Question

A 2.75-gram air inflated balloon is given an excess negative charge, q1 = -4.00 x 10^-8 C, by rubbing it with a blanket. It is found that a charged rod can be held above the balloon at a distance of d = 6.20 cm to make the balloon float. In order for this to occur, what polarity of charge must the rod possess? How much charge, q2, does the rod have? Assume the balloon and rod to be point charges. The Coulomb force constant is 1/(4 pi epsilon 0) = 8.99 x 10^9 N- m^2/C^2 and the acceleration due to gravity g = 9.81 m/s^2. q2 is neutral negative proton positive q2 = C

Explanation / Answer

since opposite charges attract each other, and the charge on the balloon is negative, the charge on the rod has to be positive.

q2 is positive.

we need to balance the weight of the balloon and the electrostatic force of attraction.so,

mg=k*q1*q2/r^2

or 2.75*10^-3*9.81 = 9*10^9*4*10^-8*q/0.062^2
or q1= +2.88*10^-7 C

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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