Video Transcript
A blue object and an orange object
move across a grid of lines spaced one meter apart. Each object moves for two
seconds. The arrows show the distances that
the objects move in each second. What is the speed of either object
relative to the other?
In this question, we’re asked to
find the speed of either of the objects shown relative to each other. From the question, we know that
each object moves for two seconds and each grid line is spaced one meter apart. Now, looking at the arrows in the
diagram, we can see that both objects are traveling in the same direction and each
object travels two meters during the two seconds.
First, we can determine the speed
of each object. Recall that speed is equal to the
distance traveled divided by the time traveled for. In this question, each object
travels two meters in two seconds. So each object has the speed of one
meter per second.
Let’s take a closer look at the
changes in the distance between these objects. Each time that the blue object
travels one meter away from the orange object, the orange object also travels one
meter and in the same direction as the blue object. Therefore, we can see that the
distance between the objects is not changing as the objects move. We can then define an equation for
relative speed, recalling that relative speed is equal to the change in distance
divided by the time.
Because there is no change in
distance between the objects, our numerator is zero, which means that the relative
speed between the objects is zero meters per second.
