Understanding Force Diagrams Quiz

Look at the diagram below. What is the correct term for this type of diagram that shows all the forces acting on an object? (Visual: A box with arrows pointing in different directions, each labeled with a force such as "gravity," "normal force," "friction," and "applied force.")

• Bar graph

• Force diagram

• Pie chart

• Line graph

Answer explanation

The diagram shows all forces acting on an object, which is specifically called a 'force diagram.' This term accurately describes the visual representation of forces like gravity, normal force, friction, and applied force.

In the force diagram below, what does the length of each arrow represent? (Visual: A single object with two arrows of different lengths pointing away from it, labeled "Force A" and "Force B.")

• The color of the force

• The direction of the force

• The strength (magnitude) of the force

• The type of object

Answer explanation

The length of each arrow in the force diagram represents the strength (magnitude) of the force. Longer arrows indicate stronger forces, while shorter arrows indicate weaker forces, making this the correct choice.

In the force diagram below, which direction does the arrow representing gravity always point? (Visual: A ball with a single arrow pointing straight down, labeled "gravity.")

• Upward

• Downward

• Left

• Right

Answer explanation

The arrow representing gravity always points downward, indicating the direction of the gravitational force acting on the ball. Therefore, the correct answer is 'Downward'.

Look at the force diagram of a box at rest on a table. Which two forces are balanced? (Visual: A box on a table with an upward arrow labeled "normal force" and a downward arrow labeled "gravity," both arrows are the same length.)

• Gravity and friction

• Gravity and normal force

• Friction and applied force

• Normal force and friction

Answer explanation

The box is at rest, meaning the forces acting on it are balanced. The upward normal force from the table equals the downward gravitational force, making gravity and normal force the balanced forces.

A student draws the force diagram below for a book sliding to the right across a table. Which force should be shown pointing to the left? (Visual: A book with a rightward arrow labeled "applied force" and a leftward arrow labeled "______".)

• Gravity

• Normal force

• Friction

• Applied force

Answer explanation

The force pointing to the left is friction, which opposes the motion of the book sliding to the right. Gravity acts downward, and the normal force acts upward, while the applied force is already shown pointing to the right.

Given the force diagram below, what can you conclude about the vertical forces acting on the object? (Visual: A block with an upward arrow and a downward arrow of equal length.)

• The object is accelerating upward

• The object is accelerating downward

• The vertical forces are balanced

• The object is moving to the right

Answer explanation

The equal length of the upward and downward arrows indicates that the forces are balanced. This means there is no net force acting on the object, so it is not accelerating in either direction.

Answer explanation

To find the net force, subtract the left force from the right force: 5 N (right) - 3 N (left) = 2 N to the right. Thus, the net force acting on the box is 2 N to the right.

A student analyzes the force diagram below and notices that the arrows representing friction and applied force are not the same length. What does this indicate about the motion of the object? (Visual: A block with a longer rightward arrow labeled "applied force" and a shorter leftward arrow labeled "friction.")

• The object is at rest

• The object is moving at a constant speed

• The object is accelerating

• The object is floating

Answer explanation

The longer applied force arrow indicates it is greater than the friction force. This net force causes the object to accelerate, meaning it is not at rest or moving at constant speed.

Answer explanation

The net force is calculated by subtracting the backward force from the forward force. Thus, 10 N (forward) - 4 N (backward) = 6 N forward. However, the vertical forces (6 N up and 6 N down) cancel each other out, leaving a net force of 4 N forward.

• The net force is zero; the block is at rest.

• The net force is up the ramp; the block is moving up.

• The net force is down the ramp; the block is accelerating down.

• The net force is perpendicular to the ramp; the block is moving sideways.

Answer explanation

The net force is calculated by subtracting the friction (2 N) from the component of gravity down the ramp (10 N). This results in a net force of 8 N down the ramp, indicating the block is accelerating down.