Position, Distance and Displacement | Physics for JAMB PDF Download

Concept of Displacement

• Displacement is a vector quantity that represents the change in position of an object from its initial point to its final point.
• It considers both the magnitude (size or distance) and the direction of the change in position.
• Displacement can be positive, negative, or zero, depending on the relative positions of the initial and final points.
• Displacement is measured in units such as meters (m) or kilometers (km).

Distinction between Distance and Displacement

• Distance is a scalar quantity that refers to the total length traveled by an object irrespective of its direction.
• It only considers the magnitude or size of the change in position.
• Distance is always positive and cannot be negative.
• Distance is measured in units such as meters (m) or kilometers (km).
• Displacement, on the other hand, takes into account both the magnitude and the direction of the change in position.

Concept of Position and Coordinates

• Position refers to the location of an object in space at a particular instant.
• It can be described using a coordinate system that provides a reference point and axes to define the position.
• A common coordinate system is the Cartesian coordinate system, which uses two perpendicular lines (x-axis and y-axis) to locate points in a two-dimensional plane.
• The position of a point is represented by coordinates (x, y), where x denotes the horizontal distance from the reference point (usually the origin) along the x-axis, and y denotes the vertical distance from the reference point along the y-axis.

Frame of Reference

• A frame of reference is a coordinate system or set of axes that establishes the context for describing the motion or position of an object.
• It provides a standard against which measurements can be made.
• Choosing an appropriate frame of reference is crucial for accurately determining distances, displacements, and positions.
• Different frames of reference can yield different measurements for the same object.

Objective Applications

Identifying Distance Traveled in a Specified Direction:

• Calculate the total distance traveled by an object by summing the magnitudes of individual displacements along the specified direction.

Using a Compass and Protractor to Locate Points/Directions:

• Utilize a compass to determine the cardinal directions (north, south, east, west) and their intermediate angles (e.g., northeast, southeast).
• Use a protractor to measure angles accurately, allowing for precise directional information.

Using Cartesian Systems to Locate Positions in the x-y Plane:

• Plot points on a Cartesian coordinate system to represent positions in a two-dimensional plane.
• Assign appropriate x and y values to locate the points accurately.
• Understand the quadrants and signs of coordinates.

Plotting Graphs and Drawing Inferences

• Represent data on a graph, with the x-axis usually denoting independent variables and the y-axis representing dependent variables.
• Interpret the shape, slope, and intercepts of the graph to draw conclusions about the relationship between variables.
• Understand concepts such as linear, quadratic, and inverse relationships, as well as the significance of the slope and y-intercept.