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Re: steering



At 09:35 AM 11/21/2003, Ludwik, you wrote:
>///the steered
> wheels (and the driven wheels too) providing a brute
> force sideward push, at the cost of scrubbing more
> or less rubber off the tread. /// A new
external force from the road appears; /// That
force would produce linear acceleration (slowing
down the center of mass). But it produces centripetal
acceleration instead; the center of mass keeps
turning at an essentially constant speed. How can
this be explained?///
Ludwik Kowalski

I suppose that this idea of acceleration is the central difficulty.
With the rest of us, you easily describe a force which adds
or takes away from an object's speed.
But a similar force which leaves the speed alone, but changes
its direction, finds a stumbling block in your students' thoughts.
Can this really be called an acceleration?
Does it meet the prerequisites?

Does a constant force associate with a constant change in velocity?
Can you identify any other factors which are necessary to procure
this change in direction?
You will say yes to the first, and no to the second, I imagine.
So this seems to meet the Newtonian case to hand.




Brian Whatcott Altus OK Eureka!