Rotating Record Frequency Calculation

[marnold1987]

A vinyl record is played by rotating the record so that an approximately circular groove in the vinyl slides under a stylus. Bumps in the groove run into the stylus, causing it to oscillate. The equipment converts those oscillations to electrical signals and then to sound. Suppose that a record turns at the rate of 33 rev/min, the groove being played is at a radius of 12.0 cm, and the bumps in the groove are uniformly separated by 0.161 mm. At what rate (hits per second) do the bumps hit the stylus?

I am totally lost on this problem...please help me.

 

[LowlyPion]

A vinyl record is played by rotating the record so that an approximately circular groove in the vinyl slides under a stylus. Bumps in the groove run into the stylus, causing it to oscillate. The equipment converts those oscillations to electrical signals and then to sound. Suppose that a record turns at the rate of 33 rev/min, the groove being played is at a radius of 12.0 cm, and the bumps in the groove are uniformly separated by 0.161 mm. At what rate (hits per second) do the bumps hit the stylus?

I am totally lost on this problem...please help me.

Welcome to PF.

How fast is the stylus moving over the vinyl?

If the bumps are registered at .161mm then how fast are they encountered at this speed?

 

[marnold1987]

I don't know where to even start on this

 

[LowlyPion]

I don't know where to even start on this

How fast is the stylus moving over the vinyl record as it rotates?

This might help:
http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html#avel

 

[marnold1987]

3.49 rad/s I think

 

[marnold1987]

oh thanks I finally figured it out with that help

 

[LowlyPion]

oh thanks I finally figured it out with that help

No problem then.

Cheers.