# Recent content by zylaxice

1. ### Doppler Shift and Beats

So the equation for the frequency heard after bouncing off the wall is just the same as if the wall was a stationary receiver with the approaching emitter? That would give the 2 equations f1 = f( 1 / (1 + VE/V) receding and f2 = f(1 / (1 - VE/V) approaching Approaching emitters...
2. ### Doppler Shift and Beats

[SOLVED] Doppler Shift and Beats Homework Statement A car horn sounds a pure tone as the car approaches a wall. A stationary listener behind the car hears an average frequency of 250Hz, which pulsates (beats) at 12 Hz. What is the speed of the car? The speed of sound is assumed to be 331...
3. ### Angular Velocity of a swinging Sphere

Thank you both, that's exactly what I did. No matter how many times I rewrote the problem, I guess I always made the same mistake. I think because my original diagram was so horrendously out of scale I somehow associated R with being the diameter of the sphere instead of the radius, and it took...
4. ### Angular Velocity of a swinging Sphere

Homework Statement A uniform solid sphere of mass M and radius R hangs from a string of length R/2. Suppose that the sphere is released from an initial position making an angle of 45 degrees with the vertical. Calculate the angular velocity of the sphere when it swings through the vertical...