Try the fastest way to create flashcards
Question

Suppose a piece of dust has fallen on a CD. If the spin rate of the CD is 500 rpm, and the piece of dust is 4.3 cm from the center, what is the total distance traveled by the dust in 3 minutes? (Ignore accelerations due to getting the CD rotating.)

Solution

Verified
Step 1
1 of 2

ω=500 revmin2π rad1 rev1 min60 s=52.36 radst=3 min60 s1 min=180 sΔθ=ωt=(52.36)(180)=9424.8 rad    s=Δθr=(9424.8)(0.043)=405.27 m\begin{align*} \omega&= 500 \text{ } \dfrac{\text{rev}}{\text{min}} \cdot \dfrac{2\pi \text{ rad}}{1 \text{ rev}} \cdot \dfrac{1 \text{ min}}{60 \text{ s}} \\ &=52.36 \text{ } \dfrac{\text{rad}}{\text{s}} \\ t&=3 \text{ min} \cdot \dfrac{60 \text{ s}}{1 \text{ min}} \\ &=180 \text{ s} \\ \Delta \theta &= \omega t \\ &=\left(52.36\right) \left(180\right) \\ &=9424.8 \text{ rad} \\ \implies s&= \Delta \theta \: r \\ &= \left(9424.8\right)\left(0.043\right) \\ &=405.27 \text{ m} \end{align*}

First, we need to convert the units of the time tt and the angular velocity ω\omega. Then, we use the formula for angular displacement to obtain Δθ\Delta \theta. In this occasion, the body rotates at a constant rate, therefore the angular acceleration is zero. Finally, we continue to calculate the traveled distance ss.

Create a free account to view solutions

Create a free account to view solutions

Recommended textbook solutions

Physics for Scientists and Engineers: A Strategic Approach with Modern Physics 4th Edition by Randall D. Knight

Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

4th EditionISBN: 9780133942651 (8 more)Randall D. Knight
3,508 solutions
Mathematical Methods in the Physical Sciences 3rd Edition by Mary L. Boas

Mathematical Methods in the Physical Sciences

3rd EditionISBN: 9780471198260 (1 more)Mary L. Boas
3,355 solutions
Fundamentals of Physics 10th Edition by David Halliday, Jearl Walker, Robert Resnick

Fundamentals of Physics

10th EditionISBN: 9781118230718 (3 more)David Halliday, Jearl Walker, Robert Resnick
8,971 solutions
University Physics, Volume 1 1st Edition by Jeff Sanny, Samuel J Ling, William Moebbs

University Physics, Volume 1

1st EditionISBN: 9781938168277Jeff Sanny, Samuel J Ling, William Moebbs
1,471 solutions

More related questions

1/4

1/7