The first of two identical boxes of mass m is sitting on level ground. The second box is sitting on a ramp that makes a 20° angle with the ground. The normal force of the level ground on the first box is ; the normal force of the ramp on the second box is . Which statement is correct?
A) = = mg.
B) = mg; = mg sin 20°.
C) = mg; = mg cos 20°.
D) = mg; = −mg cos 20°.
E) = − = −mg.

Question

The first of two identical boxes of mass m is sitting on level ground. The second box is sitting on a ramp that makes a 20° angle with the ground. The normal force of the level ground on the first box is  ; the normal force of the ramp on the second box is  . Which statement is correct? 
A) = = mg. 
B) = mg; = mg sin 20°. 
C) = mg; = mg cos 20°. 
D) = mg; = −mg cos 20°. 
E) = − = −mg.

Quizplus · Accepted Answer

The Answer of The first of two identical boxes of mass m is sitting on level ground. The second box is sitting on a ramp that makes a 20° angle with the ground. The normal force of the level ground on the first box is  ; the normal force of the ramp on the second box is  . Which statement is correct? 
A) = = mg. 
B) = mg; = mg sin 20°. 
C) = mg; = mg cos 20°. 
D) = mg; = −mg cos 20°. 
E) = − = −mg.

The First of Two Identical Boxes of Mass M Is