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## Homework Statement

A sphere and a cylinder of equal mass and radius are simultaneously released from rest on the same inclined plane and roll without sliding down the incline. Then:

A. the sphere reaches the bottom first because it has the greater inertia

B. the cylinder reaches the bottom first because it picks up more rotational energy

C. the sphere reaches the bottom first because it picks up more rotational energy

D. they reach the bottom together

E. none of the above are true

I have no idea where to even start to solve this.

A hoop, a uniform disk, and a uniform sphere, all with the same mass and outer radius,

start with the same speed and roll without sliding up identical inclines. Rank the o

according to how high they go, least to greatest.

A) hoop, disk, sphere

B) disk, hoop, sphere

C) sphere, hoop, disk

D) sphere, disk, hoop'

E) hoop, sphere, disk

I know:

hoop: I=mr

^{2}

disk: I = 1/2 mr

^{2}

sphere: I = 2/5mr

^{2}

since hoop has greatest rotational kinetic energy, it will go the highest?

9. A particle is in simple harmonic motion with period T. At time t = 0 it is halfway between

the equilibrium point and an end point of its motion, traveling toward the end point. The next

time it is at the same place is:

A. t = T

B. t = T/2

C. t = T/4

D. t = T/8

E. none of the above

I got the answer of T/4... but answer is E?

46. A simple pendulum consists of a small ball tied to a string and set in oscillation. As the

pendulum swings the tension force of the string is:

A. constant

B. a sinusoidal function of time

C. the square of a sinusoidal function of time

D. the reciprocal of a sinusoidal function of time

E. none of the above

my answer is B, since tension is greatest at the bottom of the swing and it oscillates so the tension when displayed on a F vs T graph it goes up and down like a sine function.

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