There are five naturally occurring isotopes of the element zinc. The relative 1 point abundance and mass of each are as follows. Calculate the average atomic
mass of zinc. *
64
304
Zn = 48.89%, 63.929 amu
30Zn = 27.81%, 65.926 amu
30Zn = 4.11%, 66.927 amu
30Zn = 18.57%, 67.925 amu
30 Zn = 0.62%, 69.925 amu
68
70

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.