Please show the work for both. What is the de Broglie wavelength of an electron whose kinetic energy is $1\mathrm{.}0$ eV $?$

A$)8\mathrm{.}2$ nm

B$)1\mathrm{.}2$ nm

C$)520$ nm

D$)0\mathrm{.}64$ nm

E$)52$ nm

With respect to the earth, object $1$ is moving at speed $0\mathrm{.}90$ c to the right. Object $2$ is moving to the left at speed $0\mathrm{.}70$ c with respect to object $1.$ How fast is object $2$ moving with respect to the earth?

A$)-0\mathrm{.}20c$

B$)0\mathrm{.}12$ c

C$)0\mathrm{.}540$

D$)0\mathrm{.}20$ c

E$)1\mathrm{.}6$ c