Lesson: Relative Motion Physics • 9th Grade
In this lesson, we will learn how to define the positions, displacements, and velocities of objects compared with those of other objects.
Sample Question Videos
The points a, b, c, d, and e are shown in the diagram.
How far north of a is c?
How far west of a is b?
How far south of a is e?
How far east of a is d?
How far north of e is c?
How far south of e is d?
How far east of d is b?
How far west of b is c?
An airplane flying horizontally in a straight line moves parallel to the ground at a speed of 450 m/s. A second airplane flies below, in the opposite horizontal direction, moving parallel to the ground at a speed of 100 m/s. Which of the diagrams (a), (b), (c), and (d) correctly shows how the velocities of the airplanes can be combined to find the speed at which the airplanes move relative to each other?
Snowflakes in a snowstorm fall vertically downward at 0.12 m/s. The snowflakes fall in the air around a 1.6 m tall traveler who walks across the snowy ground at 0.72 m/s. The snowflakes are blown eastward at 0.36 m/s by the wind. Consider snowflakes to be initially located directly above the traveler’s head and at the height above the ground of the top of the traveler’s head.
The traveler walks westward. What distance east of the traveler does a snowflake land?
The traveler walks eastward. What displacement east of the traveler does a snowflake land?