This question stemmed from a conversation about measuring the speed of two very different objects. I realized that, unlike other measures that have their own units (length, mass, etc.), speed is measured using a ratio of distance and time. So I was wondering, does the size of the objects get factored into the measurement somehow? If speed is only ever measured using this distance/time approach (mph, for example), then wouldn’t the measure of speed become problematic since a large object is able to cover more distance than a small object?
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Speed and velocity are relative. What this means is that one object can only be assigned a velocity relative to a reference frame.
Basically, a car may only be moving 20 mph relative to the Earth’s surface, but 40 mph relative to an oncoming car, or 67,020 mph relative to the sun etc.
Large objects do not move faster than small objects. If we take something like the earth, we might use the center of it as it’s reference for distance in respect to other objects in space.
However, if you throw a ball, we will typically use the Earth’s surface as a reference point for speed.
When people say things like, “velocity is relative” they mean it entirely literally. There is no such thing as the velocity of an object without something else to relate it to.
TLDR; No. Speed and velocity are relative and by definition equal to Delta D / Delta T. Size doesn’t matter for this.
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