Question

2. Two pieces of space junk are floating together in the same orbit near a damaged satellite. Both are neutral spheres, with diameters of 50cm and 100cm. A storage battery on the satellite explodes, sending ions in all directions and contaminating the spheres, which acquire charges. The smaller one has a charge of -10°C and the larger carries +20PC. Their surfaces are initially 4.5m apart. (a) What is the electric field midway between the centers of the spheres? (b) What is the potential energy of the two-sphere system? (c) The spheres drift toward each other, of course. When their surfaces collide, what is the kinetic energy of the system?

Answer 1

B NA = 0.25m ro= 0.5om VA d=4.5M 26 = +2ouc 9A=-100c LB ใA. YE EA+EB Ep = EA+EB + klo KLA 72 SA=XB = 1 = 2.625m 10x15c + 2oxiol 9x10x (2.6252 Nic 3.92 x 10 3.918x10x105 Ep = 9x108x (-10x10%) × 20x10 b U=KLALB 5.25 -1 3:42880 -0.34 T C from energy conservation Uitki = Uft kf 1 Ui= -0.34J Ki=OJ KIALB Uf = r=rAtro= 0.75m -2.4J Ur = -9x109 10x20x10 0.75 -0.34to= - 2.4+ kr Kf= 2.06J