AP Physics B Geeks...Help?

Test Preparation
1

<li><p>A particle travels in a circular path of radius 4 m at constant speed. The net force on the particle is 60 N. The kinetic enregy of the particle is
(A) 40 J
(B) 60 J
(C) 120 J
(D) 140 J
(E) Cannot be determined from the given information.</p></li>
<li><p>An object with a mass of 5 kg is attached to a 1 meter long rope and whirled in a vertical circle. At the bottom of its path, the rope has a tension of 95 N. The object is moving most nearly
(A) 2 m/s
(B) 3 m/s
(C) 6 m/s
(D) 9 m/s
(E) 15 m/s</p></li>
<li><p>What is the maximum speed a vehicle can travel along a circular turn without leaving the road? The turn has a radius of 50 m. The road has a coefficient of kinetic friction of .20.
(A) 5 m/s
(B) 10 m/s
(C) 15 m/s
(D) 20 m/s
(E) 25 m/s</p></li>
<li><p>A 10 kg object moving in a horizontal circle of radius 5 m experiences a centripetal force of 50 N. What is the velocity of the object?
(A) 0.5 m/s
(B) 1 m/s
(C) 2.5 m/s
(D) 5 m/s
(E) 25 m/s</p></li>
<li><p>A 3 N force is exerted on an infinitely large wheel of moment of interial 12 kgm^2. At what distance from the center of the wheel should the force be exerted in order for the wheel to accelerate with an angular acceleration of 2 rad/s^2, assuming the force is exerted perpendicular to the radius of the wheel in the plane of the wheel?
(A) 6 m
(B) 8 m
(C) 12 m
(D) 16 m
(E) 18 m</p></li>
<li><p>A mass m oscillates on a spring of spring constant k with an amplitude A. What is the maximum velocity of the mass?
(A) A
(B) A(k/m)
(C) A(m/k)
(D) A<em>sqrt(k/m)
(E) A</em>sqrt(m/k)</p></li>
<li><p>A pendulum swinging with a maximum amplitude of pi/6 has a period of T. If the maximum amplitude is increased to pi/3, what is the new period of the pendulum?
(A) T/4
(B) T/2
(C) T
(D) 2T
(E) 4T</p></li>
<li><p>A pendulum swings in simple harmonic motion with period T and angular displacement theta. If the same pendulum is instead raised to an initial displacement of 3theta, the new period will be
(A) T/9
(B) T/3
(C) T
(D) 3T
(E) 9T</p></li>
</ol>

<p>Please help me with these. Thanks. I have a midterm this wednesday.</p>

2

<p>11 is E, you need the mass to get kinetic energy</p>

3

<p>12 is B......</p>

4

<p>18 is B..........</p>

5

<p>19 is D..........</p>

6

<p>lol ckmets13, you certainly seem to know everything abt physics. lol.</p>

<p>I'm taking AP Physics now (didn't take reg physics) and I think my course is for AP Physics C so not sure :/</p>

7

<p>OmgItsCollege, same here. My teacher teaches us AP Physics B and C, but we'll be taking the Physics B exam. Thats more to study for. OMG></p>

8

<p>Yeah...and there's supposed to be a second part to the AP Physics C test that our class barely touches on. Many people from last year got 5's on the C but 3's and lower on the sub-section or whatever it is...</p>

9

<p>For 11, couldn't you do something like this...</p>

<p>60 = m(v^2/4)
240 = mv^2</p>

<p>KE = (1/2)mv^2
KE = (1/2)(240) = 120 J ?</p>

10

<p>You sure thats right setzwxman ?</p>

11

<p>11 is C.</p>

<p>Same as above, just extra steps shown.</p>

<p>Since, the particle is moving in a circle,</p>

<p>Fc = (mv^2)/r
60 = (mv^2)/4
240 = (mv^2)</p>

<p>KE = 1/2(mv^2)
KE = 1/2(240)
KE = 120J</p>

12

<p>IT seems like a typical move pulled by ETS in several of their tests, most notably the SAT Reasoning Test. Let a group of variables perform as a single one. I suppose it is a cool concept.</p>

13

<p>that seems like ap physics c problems. but wait actually its just our teacher that gives us practice ap physics b problems even though we are in C. thats what happens when u have an underqualified teacher.</p>

14

<p>11-C; 12-B; 18-B; 19-D; 30-B; 49-D; 51-C; 61-C (First questions only use F=mv^2/r) (Period depends on gravity and length of the pendulum) (for 49, 1/2<em>kA^2=1/2</em>mV^2),(question 30 is ap physics C, but i solved it only by using the units--I am not sure, though)</p>

15

<ol>
<li>A rod is balanced over a pivot with masses m and M positioned such that the system is in static equilibrium. If the mass M is a distance d away, and the mass m is a distance d/4 away, what is the ratio of M to m?
(A) 4:1
(B) 2:1
(C) 1:1
(D) 1:2
(E) 1:4</li>
</ol>

16

<p>24-E (if away means distance from the pivot) M<em>d=m</em>d/4</p>