Physics sat2, urgent help!

Test Preparation SAT Subject Test Preparation
1

<p>Hey guys.. so I'm going to take the physics SAT2 and have already covered everything regarding mechanics, thermal physics, waves, and optics</p>

<p>Now i just have electricity and magnetism and modern physics left. I self-studied the rest with the help of my general physics class. I am currently using Princeton Review. Is it possible to self-study electricity and magnetism and modern physics on my own through princeton review and sparknotes by november 7th?</p>

<p>Oh and really how hard are the electricity and magnetism questions on the sat2?</p>

<p>Thanks a lot guys.</p>

2

<p>What if we said that it was impossible?</p>

3

<p>Nothing is impossible. If you all DO happen to say that it is impossible, then I’ll either seek information from more reliable sources, or continue on with my studying and get as much done as I can before the 7th of Novemeber.</p>

4

<p>the hardest or maybe the only hard one is magnetism, the rest is easy.</p>

5

<p>Magnetism is a tad tricky, and if you have no chemistry background, parts of the modern physics might throw you off, but don’t worry, I got through the same situation (except worse. I didn’t do waves, parts of thermo, electricity, modern physics, or optics at all), and still managed a 800. If you’re self reliant and you know how to teach yourself concepts, you’ll be fine (because you’ll have to do this in college, so it’s good to start now)</p>

6

<p>So here is a question from Barron’s 8th Edition:</p>

<p>An object with a constant mass rest on a smooth and perfectly horizontal table. If a horizontal force “F” is applied, acceleration “a” results. If the 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>I chose “E”, because I thought only II is the correct one, but the answer given in the book is “C”. Can someone explain?</p>

7

<p>the answer cannot be C
C states that (II) the acceleration will be doubled AND (IV) the acceleration will increase but not double.</p>

<p>That in itself is contradictory, and the answer IS in fact E, none of the above, since only II is true.</p>

<p>Say F is initally 2 N, and the constant mass of the object is 2 kg.</p>

<p>F=ma<br>
2=2a
a=1</p>

<p>Now say that F is doubled. Remember that the mass is still 2 kg.
F=ma
2(2)=2a
4=2a
a=2</p>

<p>The acceleration is doubled.</p>

8

<p>I used the exact same logic. That is just a mistake in the book I guess…</p>

<p>By the way, it is question no.58 in the diagnostic test.</p>

9

<p>naw, the answer is right, the question didn’t say if the surface is frictionless or not.</p>

10

<p>Smooth indicates that fricition is negligible.</p>

11

<p>It cannot be C. Either II or IV is possible assuming ‘Smooth’ is not well defined. I would choose E.</p>

12

<p>Can one eat the cake and have it at the same time? Can the acceleration double and be less than double at the same time ?</p>

13

<p>Some things really are impossible :slight_smile: Anyway, if there is friction, then the answer would actually be D: the new net force (2F - friction) is not double the old net force (F - friction). But normally, “smooth” is used to mean “frictionless”. In any case, answer C is self-contradictory. Not unusual in Barron’s to have mistakes or poorly worded problems, IMO.</p>

14

<p>fignewton, well said. It is a bad question. If it changed to D.) II only, it would be a good question.</p>

15

<p>actually, if there’s friction, the acceleration will more than double. So C can be right.</p>

<p>If there’s no friction, the acceleration will double, if there is, the accleration will more than double</p>

16

<p>the question is wrong, for sure.</p>

17

<p>so getting back to the REAL topic of this thread :stuck_out_tongue:
what aspects of electricity are most of the questions based on?</p>

18

<p>

</p>

<p>That is just not possible! If there’s friction, the acceleration will be double, but if there’s no friction then acceleration can’t be more than double, it could be less than double, because some of the force would then be consumed in overcoming the friction.</p>

19

<p>How important is the double slit experiment?</p>

20

<p>Seconding the question about the double slit experiment. So bump, I guess.</p>