Effectively, how many valence electrons are there in each atom within q silicon crystal?​

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

Aload of 10kn is to be suddenly applied to the free end of a vertical rod of length 500 mm, the upper end being rigidly fixed. 190 mechanical science what should the diameter of the rod be if the maximum stress in the rod is not to exceed 100 mpa? the tensile modulus of the rod is 205 gpa.