displacement
A vector quantity that denotes distance with a directional component.
The length and direction of a straight line between two objects.
Examples of displacement in the following topics:

Flotation
 But the Archimedes principle states that the buoyant force is the weight of the fluid displaced.
 When any boat displaces a weight of water equal to its own weight, it floats.
 The same is true for vessels in air (as air is a fluid): A dirigible that weighs 100 tons displaces at least 100 tons of air; if it displaces more, it rises; if it displaces less, it falls.
 If the dirigible displaces exactly its weight, it hovers at a constant altitude.
 The volume submerged equals the volume of fluid displaced, which we call $V_\mathrm{fl}$.

Reference Frames and Displacement
 Frames of reference are particularly important when describing an object's displacement.
 Displacement is the change in position of an object relative to its reference frame.
 The word "displacement" implies that an object has moved or has been displaced.
 where Δx is displacement, xf is the final position, and x0 is the initial position.
 Notice that the arrow representing his displacement is twice as long as the arrow representing the displacement of the professor (he moves twice as far).

Force in the Direction of Displacement
 The work done by a constant force is proportional to the force applied times the displacement of the object.
 As we have shown, this is proportional to the force and the distance which the object is displaced, not moved.
 Calculate the work done on the box if the box is displaced 5 meters.
 (1.b) Since the box is displaced 5 meters and the force is 2 N, we multiply the two quantities together.
 Regardless of how long it takes, the object will have the same displacement and thus the same work done on it.

Average Velocity: A Graphical Interpretation
 Average velocity is defined as the change in position (or displacement) over the time of travel.
 In contrast, average velocity is defined as the change in position (or displacement) over the total time of travel .
 When calculating average velocity, however, you are looking at the displacement over time.
 Because you walked in a full rectangle and ended up exactly where you started, your displacement is 0 meters.
 Therefore, your average velocity, or displacement over time, would be 0 m/s.

Position, Displacement, Velocity, and Acceleration as Vectors
 Position, displacement, velocity, and acceleration can all be shown vectors since they are defined in terms of a magnitude and a direction.
 Most commonly in physics, vectors are used to represent displacement, velocity, and acceleration.
 In physics, vectors are useful because they can visually represent position, displacement, velocity and acceleration.
 Displacement is defined as the distance, in any direction, of an object relative to the position of another object.
 Physicists use the concept of a position vector as a graphical tool to visualize displacements.

The Simple Pendulum
 For small displacements, a pendulum is a simple harmonic oscillator.
 We begin by defining the displacement to be the arc length s.
 The displacement s is directly proportional to θ.
 where the force constant is given by k=mg/L and the displacement is given by x=s.
 The linear displacement from equilibrium is s, the length of the arc.

Simple Harmonic Motion
 Simple harmonic motion is a type of periodic motion where the restoring force is directly proportional to the displacement.
 Simple harmonic motion is a type of periodic motion where the restoring force is directly proportional to the displacement (i.e., it follows Hooke's Law) .
 where m is the mass of the oscillating body, x is its displacement from the equilibrium position, and k is the spring constant.
 Each of these constants carries a physical meaning of the motion: A is the amplitude (maximum displacement from the equilibrium position), ω = 2πf is the angular frequency, and φ is the phase.
 Relate the restoring force and the displacement during the simple harmonic motion

Pictures of Modes
 ., places where the displacement is zero).
 These are two snapshots of the instantaneous displacement of the plane when being driven in one of its modes.

Conditions for Wave Interference: Reflection due to Phase Change
 When two or more waves are incident on the same point, the total displacement at that point is equal to the vector sum of the displacements of the individual waves.
 If a crest of one wave meets a crest of another wave of the same frequency at the same point, then the magnitude of the displacement is the sum of the individual magnitudes.
 In this case, the magnitude of the displacements is equal to the difference in the individual magnitudes, and occurs when this difference is an odd multiple of π.
 If the difference between the phases is intermediate between these two extremes, then the magnitude of the displacement of the summed waves lies between the minimum and maximum values.

Longitudinal Waves
 Like transverse waves, longitudinal waves do not displace mass.
 It is important to remember that energy, in this case in the form of a pulse, is being transmitted and not the displaced mass.
 Matter in the medium is periodically displaced by a sound wave, and thus oscillates.