A vinyl record makes 90 rotations in a minute. The diameter of the disk is 34 cm. Find the linear velocity of a point on the circumference of the disk in m/s.

Respuesta :

Answer: 1.6 m/s

Explanation:

The relationship between linear speed and angular speed for a rotational motion is

[tex]v=\omega r[/tex]

where

v is the linear speed

[tex]\omega[/tex] is the angular speed

r is the distance from the axis of rotation

For the vinyl record here, we have:

[tex]\omega=90 rev/min[/tex]

Keeping in mind that

[tex]1rev = 2\pi rad\\1 min =60 s[/tex]

We can convert it to rad/s:

[tex]\omega = 90 \cdot \frac{2\pi}{60}=9.4 rad/s[/tex]

The diameter of the disk is 34 cm, so the radius is

[tex]r=\frac{34}{2}=17 cm = 0.17 m[/tex]

Therefore, the linear velocity of  a point on the circumference is

[tex]v=(9.4)(0.17)=1.6 m/s[/tex]