A 20 Kg-Book Is at Rest on the Horizontal Floor

Multiple Choice

A 2.0 kg-book is at rest on the horizontal floor. You are applying a 10 N downward force, on the book, at an angle of 60 ^o from the horizontal. The normal force on the book exerted by the floor is

A) 5.0 N.
B) 10 N.
C) 25 N.
D) 28 N.
E) 30 N.