Interstellar space has an average temperature of about 10 k , and an average density of hydrogen atoms of about one hydrogen atom per cubic meter. calculate the mean free path of hydrogen atoms in interstellar space. use =100 pm as the diameter of a hydrogen atom.

meter the mean free path of hydrogen atoms in interstellar space.Explanation:

The mean free path equation is given as:

Where"

d = diameter of hydrogen atom in meters

n =  number of molecules per unit volume

We are given: d = 100 pm =

meter the mean free path of hydrogen atoms in interstellar space.

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.