This web article is reviewing an electric motorbike that can go from 0 to 60 MPH in under one second. In comparing the accelerating of the bike, the article says:
All this gives the driver a G-force three times more than that faced by a skydiver during freefall!
Er.. come again?
G-force, the way it is used for the public, is simply the amount of "reaction" force that we feel. When doing a looping roller coaster, it is the amount of force the seats exert back onto us. That's why at the bottom of a loop, you get G-force greater than "g", the gravitational acceleration at the earth's surface (9.8 m/s^2), while at the top of a bump, you could get "negative G's", meaning it is less than g.
So what's the G-force experienced by a skydiver? If you ignore air resistance, it should be.... er... ZERO! Free falling, by definition, implies that there's no reaction force. That's how the "vomit plane" works when people are training for weightless environment - the plane makes a free fall every few minutes, and every entity in the object will feel no reaction from the floor of the plane since everything is free falling. So equating the bike's acceleration as having three times the G-force experience by a skydiver is rather puzzling.
Now, one could argue that maybe the writer was thinking about the G-force experienced by the skydiver after he/she reaches terminal velocity, which would make the G-force to be equal to g. Assuming that the writer is smart enough to know basic mechanics AND know about terminal velocity, then the comparison is also puzzling. If it is just a simple "g", then why not compare it to the regular person standing still on the ground? After all, it IS the same thing and I'm guessing, A LOT more people are more familiar with standing still on the ground than skydiving.
Nope. I think this is a mistake of comparison.
Zz.
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