The question true or false

17) The resultant shearing stress on the plane e, is given by T1 = T21e2 + T31@3. ( ) 18) Symmetry of the stress tensor is proved from the principal of linear momentum. 19) The third principle invariance of the stress tensor is I3 = T11 +T22 + T33 20) The stress power P, represents the rate at which work is done to change the volume and shape of a particle of unit volume. 21) The stress power Ps is given by Ps = det(TD). 22) The vector q is a vector whose magnitude gives the net heat flow across a unit area by conduction () 23) the net heat flow by conduction Qc into a differential element is lc = -(divq)dv. 24) For a steady-state temperature distribution in the body, there should be no net rate of heat flow either in or out at every point in the body. ( ) 25) The fundamental postulate of conservation of energy states that the rate of increase of internal and kinetic energy for a particle equals the work done on the material plus heat input through conduction across its boundary surface and heat supply throughout its volume. 26) The rate of work done on the particle by body forces and surface forces is given by () 1 P= Dt Dolov?) + |+ Tij avi xj