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A LP record rotates at an angular velocity of 33.3 RPM It takes 25 minutes to play one side the How many grooves does each have?

Given:

Angular velocity, \(\omega = 33.3\) RPM = \(33.3 \times \frac{2\pi}{60} = 3.49\) rad/s

Time to play one side, \(t = 25\) min = \(25 \times 60 = 1500\) s

To find:

Number of grooves on each side, \(n\)

The linear velocity of the record at the outermost groove is given by:

$$v = \omega R$$

Where \(R\) is the radius of the record.

The circumference of the record at the outermost groove is:

$$C = 2\pi R$$

The number of grooves on each side is equal to the circumference of the record divided by the groove spacing:

$$n = \frac{C}{d}$$

Where \(d\) is the groove spacing.

Substituting the expressions for \(C\) and \(v\) into the equation for \(n\), we get:

$$n = \frac{2\pi R}{\omega t}$$

Substituting the given values, we get:

$$n = \frac{2\pi \times 0.15 \ m}{3.49 rad/s \times 1500 s}$$

$$n \approx 1100 \text{ grooves}$$

Therefore, each side of the LP record has approximately 1100 grooves.

Recording Music

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