Estimate (a) the maximum, and (b) the minimum thermal conductivity values (in w/m-k) for a cermet that contains 83 vol% carbide particles in a metal matrix. assume thermal conductivities of 28 and 66 w/m-k for the carbide and metal, respectively.

  k_max = 31.82 w/mk

  k_min  = 17.70 w/mk

Explanation:

a) the maximum thermal conductivity is given as

where k_m is thermal conductvitiy of metal

k_p is thermal conductvitiy of carbide

v_m = proportion of metal in the cement = 0.17

v_p = proportion of carbide in the cement = 0.83

            = 66*0.17 + 28*0.83

           k_max = 31.82 w/mk

b) the minimum thermal conductivity is given as

          = \frac{28+66}{28*0.17 +66*0.83}

       k_min  = 17.70 w/mk

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

it breaks and dirupture other materials and other sencews from the bottom