Question

predicting motion from a force diagram
force diagram: a dot with upward arrow ( f_n ), downward arrow ( f_g ), leftward arrow ( f_f ), rightward arrow ( f_p )
options (checkboxes):
the book is at rest.
the net force is zero
the forces are unbalanced.
the book is moving to the right.
the forces are balanced.
the net force is to the right.

Explanation:

To solve this, we analyze the force diagram:

Step 1: Vertical Forces

In the vertical direction, \( F_N \) (normal force) and \( F_g \) (gravity) are equal in magnitude and opposite in direction, so they balance (\( F_N = F_g \), net vertical force \( = 0 \)).

Step 2: Horizontal Forces

In the horizontal direction, \( F_p \) (applied force, right) and \( F_f \) (friction, left) are shown. If \( F_p > F_f \) (visually, \( F_p \)’s arrow is longer, implying greater magnitude), the horizontal forces are unbalanced.

Step 3: Net Force and Motion

• Balanced/Unbalanced? Vertical forces balance, but horizontal forces do not (since \( F_p

eq F_f \)) → forces are unbalanced.

• Net Force Direction? Since \( F_p > F_f \), net force is \( F_p - F_f \) (to the right).
• Motion? Unbalanced net force to the right means the block accelerates (or moves) to the right.
• Net Force Zero? No, because horizontal forces are unbalanced.
• At Rest? No, because net force is non - zero (so it can’t be at rest or moving at constant velocity).

Correct Statements (Checkboxes):

• "The forces are unbalanced" (because horizontal forces differ, vertical balance doesn’t make all forces balanced).
• "The block is moving to the right" (net force right causes motion/acceleration right).
• "The net force is to the right" (since \( F_p > F_f \), net force \( = F_p - F_f \), direction right).

(If the question is to identify correct statements, these are the valid ones. If it’s a multiple - choice with these as options, select them.)

Answer:

To solve this, we analyze the force diagram:

Step 1: Vertical Forces

In the vertical direction, \( F_N \) (normal force) and \( F_g \) (gravity) are equal in magnitude and opposite in direction, so they balance (\( F_N = F_g \), net vertical force \( = 0 \)).

Step 2: Horizontal Forces

In the horizontal direction, \( F_p \) (applied force, right) and \( F_f \) (friction, left) are shown. If \( F_p > F_f \) (visually, \( F_p \)’s arrow is longer, implying greater magnitude), the horizontal forces are unbalanced.

Step 3: Net Force and Motion

• Balanced/Unbalanced? Vertical forces balance, but horizontal forces do not (since \( F_p

eq F_f \)) → forces are unbalanced.

• Net Force Direction? Since \( F_p > F_f \), net force is \( F_p - F_f \) (to the right).
• Motion? Unbalanced net force to the right means the block accelerates (or moves) to the right.
• Net Force Zero? No, because horizontal forces are unbalanced.
• At Rest? No, because net force is non - zero (so it can’t be at rest or moving at constant velocity).

Correct Statements (Checkboxes):

• "The forces are unbalanced" (because horizontal forces differ, vertical balance doesn’t make all forces balanced).
• "The block is moving to the right" (net force right causes motion/acceleration right).
• "The net force is to the right" (since \( F_p > F_f \), net force \( = F_p - F_f \), direction right).

(If the question is to identify correct statements, these are the valid ones. If it’s a multiple - choice with these as options, select them.)