Arubber balloon is rubbed with a pvc pipe and the rubber balloon becomes positively charged. why is this? a) because the rubber balloon gained protons from the pvc pipe. b) because the rubber balloon gained electrons from the pvc pipe. c) because the rubber balloon lost protons to the pvc pipe. d) because the rubber balloon lost electrons to the pvc pipe

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.