Re: Car acceleration

[John Mallinckrodt <ajmallinckro@CSUPOMONA.EDU>]

> A car accelerates forward from a stop sign.  Air resistance slows
> the motion.  What force causes the car to accelerate forward?
> A) It's weight
> B) The force of the engine on the tires
> C) The friction on the car from the road
> D) The upward force exerted on the car by the road
> E) The force of the driver on the accelerator pedal

As with some if not most others, it is clear to me that the
intended answer is C, but lest my previous arguments for that view
be misunderstood, I want to go on record as agreeing that the
problem itself is inexcusably poorly worded.  Beyond the proper
objections that have already been registered, I would also note
that the problem statement is self contradictory.  The car can not
simultaneously have a motion that "slows" and also "accelerate
forward."

John Mallinckrodt      mailto:ajm@csupomona.edu
Cal Poly Pomona          http://www.csupomona.edu/~ajm