Consider a 45-cm-long journal bearing that is lubricated with oil whose viscosity is 0.1 kg/m·s at 20°c at the beginning of operation and 0.008 kg/m·s at the anticipated steady operating temperature of 80°c. the diameter of the shaft is 8 cm, and the average gap between the shaft and the journal is 0.08 cm. determine the torque needed to overcome the bearing friction initially and during steady operation when the shaft is rotated at 1450 rpm.

To understand the electric potential and electric field of a point charge in three dimensions consider a positive point charge q, located at the origin of three-dimensional space. throughout this problem, use k in place of 14? ? 0. part adue to symmetry, the electric field of a point charge at the origin must point from the origin. answer in one word. part bfind e(r), the magnitude of the electric field at distance r from the point charge q. express your answer in terms of r, k, and q. part cfind v(r), the electric potential at distance rfrom the point charge q. express your answer in terms of r, k, and q part dwhich of the following is the correct relationship between the magnitude of a radial electric field and its associated electric potential ? more than one answer may be correct for the particular case of a point charge at the origin, but you should choose the correct general relationship. a)e(r)=dv(r)drb)e(r)=v(r)rc)e(r)=? dv(r)drd)e(r)=? v(r)r