Question

Two insulating spheres have radii 0.300 cm and 0.500 cm, masses 0.100 kg and 0.700 kg, and uniformly distributed charges of -2.00 µC and 3.50 µC. They are released from rest when their centers are separated by 1.00 m.

(a) How fast will each be moving when they collide? (Hint: Consider conservation of energy and of linear momentum.)
__________m/s (lighter sphere)
__________m/s (heavier sphere)

(b) If the spheres were conductors, would the speeds be greater or less than those calculated in part (a)? (Note: Assume a reference level of potential V = 0 at r = ∞.)

(greater, the same, or less than) choose one and explain answer

Answer 1

a) From the conservation of linear momentum The initial potential energy is, U, Is negative because it is a bound system When the sphere is collide, the electric potential energy is, 12 From the conservation of energy 2 2 2 2 m 9192 2m,kq.gh 2(0.7)(9 x 109)(2x10-6)(35x10-6 )/ 1 0.003 +0.005 1 11.7m/s And (0.7) 1.67 m/s