Help with these 2 Questions

The de broglie relation λ=h/p can be rewritten in terms of the wave number k as p=kℏ. recall that wave number is defined by k=2π/λ. using the fact that λ=v/f, find the wave numbers k1 and k2 corresponding to frequencies f1 and f2. express your answer as two expressions

What makes thermal imaging cameras useful? they can detect differences in color. they can detect differences in wave speeds. they can detect differences in temperature. they can detect mechanical waves.

Could someone me find the answer to this problem.