Question

why did einstein write a letter to franklin d

Answer 1

For cautioning him on the effect of the Atomic bomb. He said if Atomic bomb was dropped on the port of America it could cause significant damage to the port and surrounding areas.

Answer 2

$\huge\bold\purple{hey \: mate}$

The Nazi's had acquired the knowledge of making an atom bomb. It was a very destructive weapon. It could destroy the whole part of the world. The situation demanded that Einstein should write a letter to Franklin Roosevelt.

$\bold\purple{hope \: it \: will \: helps \: u}$