<p>Hey, I recently bought the Barron's Physics book for the SAT II and was taking the diagnostic test when I got up to this question. I was just dumbfounded; either I'm missing something or this book is illogical.</p>
<p>An object with a constant mass rests on a smooth and perfectly horizontal table. If a horizontal force F is applied, acceleration a results. If F is doubled without changing the direction, what will be the effect(s) on the acceleration?</p>
<p>I. The acceleration will remain the same.
II. The acceleration will be doubled.
III. The acceleration will decrease.
IV. The acceleration will increase but not double.</p>
<p>A) I, II, and III only.
B) I and III only
C) II and IV only
D) IV only
E) None of the above</p>
<p>How is the answer C? Is this not a complete contradiction? It is just worded poorly...does it really mean what could happen?</p>
<p>shouldn't it just be 2, using the formula F=ma?</p>
<p>Yes, that's what I thought...</p>
<p>seems like it should just be 2 to me also.. just throwing some ideas out.. is friction taken into account or the angle of the force (components?) idk seems like a vague question</p>
<p>Probably just a messed up answer. The answer to the question is obviously C.</p>
<p>To me, smooth and perfectly horizontal imply frictionless and 180 degrees. The question was copied exactly how it was written on the workbook; but, there are other ones (not as bad) like this where the answers are a bit far fetched and worded very poorly. I must say, do not buy this is you're preparing for physics.</p>
<p>Hello. I also bought the Barron's book and it has been one of the worst Prep books. I used it for the SAT Math IIC, and it was great. Unfortunately, the Physics edition is blatantly erroneous. As you take the rest of the tests, there are several mistakes (I think thats how they are testing how well we know the material - by recognizing their mistakes).</p>