A 20-Kg Book Is on the Floor of an Elevator

Multiple Choice

A 2.0-kg book is on the floor of an elevator. If the elevator is moving upward at a constant speed of 5.0 m/s, the normal force acting on the book is

A) 0 N.
B) 2.0 N.
C) 5.0 N.
D) 10 N.
E) 20 N.