# Question Video: Determining the Speed of an Object Relative to a Set of Grid Lines Science

An orange object moves across a grid of lines spaced 1 meter apart. The object moves for 2 seconds. The arrow shows the distance that the object moves in each second. What is the speed of the object relative to the grid lines that it crosses?

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### Video Transcript

An orange object moves across a grid of lines spaced one meter apart. The object moves for two seconds. The arrow shows the distance that the object moves in each second. What is the speed of the object relative to the grid lines that it crosses?

Here, we are asked to find the speed of an object relative to a grid line that the object crosses. All the grid lines are stationary. This means that the motion of an object toward or away from a grid line is the only thing that affects the speed of the object relative to the grid line.

We see then that our equation for speed will just depend on the change in distance of the object. Remember that the speed of an object is the distance traveled by the object divided by the time that the object travels for.

Looking at this diagram, we can see that in the two seconds that the object is moving, it has traveled past two grid lines. These lines are spaced one meter apart. This means that the object traveled two meters in two seconds.

Now let’s look at our equation for speed and substitute these values. Speed is equal to distance traveled, two meters, divided by the time it takes to travel that distance, two seconds. So the speed is equal to two meters divided by two seconds. Simplifying this will give us the speed of one meter per second. This is the speed of the object relative to the grid lines that it crosses.