"alexy" wrote in message
...
"muff528" wrote:

Uh-Oh!!.....here we go again!

I vote -- 120
Kinda like an escalator. You can still go up on a "down" escalator
if you run. The treadmill would have to be "set" at the 60 mph speed
so that the car's "input" would not affect it.
But that would change the problem. In the problem as stated, you would
have to have a device that determined the cars forward speed (NOT its
wheel speed) and feed that input to the speed regulator on the
treadmill.

OK -- I'll stand corrected on that part of my post. But the car's
speedometer will do just fine. The car's (and the belt's) speed relative to
the ground will be half of the indicated speed if we continue to meet the
"equal speed" condition.