threewingedfury

ok cool - I just didnt think people would want to deal with so many questions lol


The displacement of an object oscillating on a spring is given by x(t)=xmcos(wt+p). If the initial displacement is zero and the initial velocity is in the negative x direction, then the phase constant p is:
a. 0 rad
b. pi/2 rad
c. pi rad
d. 3pi/2 rad
e. 2pi rad
I figured this one was d.


Two uniform circular disks have the same mass and the same thickness are made from different materials. The disk with the smaller rotational inertia is:
a. the one made from the more dense material
b. the one made from the less dense material
c. neither - both are the same
d. the disk with the larger angular velocity
e. the disk with the larger torque
I thought this one was b.


A hoop (I=MR^2) rolls with constant velocity and without sliding along level ground. Its rotational kinetic energy is:
a. half its translational kinetic energy
b. the same as its translational kinetic energy
c. twice its translational kinetic energy
d. four times its translational kinetic energy
e. one third its translational kinetic energy
This one, I have no clue.


When a certain rubber band is stretched a distance x, it exerts a restroing force of magnitude F = ax+bx^2 where a and b are constants. The work done in stretching this rubber band from x = 0 to x = L is:
a. aL^2 + bLx^3
b. aL + 2bL^2
c. a + 2bL
d. bL
e. aL^2/2 +bL^3/3
No clue on this one either.


Vectors A and B have magnitude L. When drawn with their tails at the same point, the angle between them is 30 degrees. The value of A dot B is
a. zero
b. L^2
c. square root(3)L^2/2
d. 2L^2
e. none of these


Vectors A and B have magnitude L. When drawn with their tails at the same point, the angle between them is 60 degrees. The value of A x B is
a. zero
b. L^2
c. square root(3)L^2/2
d. 2L^2
e. none of these

I really hate this stuff - I just cant get a grasp of it.