Can the average speed of a trip be greater than the size of its average velocity?
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Can the average speed of a trip be greater than the size of its average velocity? Explain, and work out an example: a girl walks east and then west in .
Need a reminder? The key ideaShow
Speed distance time; velocity displacement time. Average speed total distance total time. .
Distance is the length of the whole path; it has no direction and never decreases. Displacement is the straight line from start to end, with a direction. On a straight road use signs; for a right-angle turn, displacement .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The idea. The distance is never less than the displacement, so the average speed is never less than the size of the average velocity. They are equal only for a straight line with no turning back.
Step 2. Example. Average speed ; average velocity east.
Answer: Yes. Here against .
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