A belt runs a pulley of radius 8 inches at 60 revolutions per minute. a) Find the angular speed in radians per minute. b) Find the linear speed in inches per minute.

Respuesta :

Answer:

Part a) [tex]120\pi\ \frac{rad}{min}[/tex]

Part b) [tex]960\pi\ \frac{in}{min}[/tex]

Step-by-step explanation:

we have

60 rev/min

Part a) Find the angular speed in radians per minute

we know that

One revolution represent 2π radians (complete circle)

so

[tex]1\ rev=2\pi \ rad[/tex]

To convert rev to rad, multiply by 2π

[tex]60\ \frac{rev}{min}=60(2\pi)=120\pi\ \frac{rad}{min}[/tex]

Part b) Find the linear speed in inches per minute

we know that

The circumference of a circle is equal to

[tex]C=2\pi r[/tex]

we have

[tex]r=8\ in[/tex] ----> given problem

substitute

[tex]C=2\pi(8)[/tex]

[tex]C=16\pi\ in[/tex]

Remember that

One revolution subtends a length equal to the circumference of the circle

so

[tex]1\ rev=16\pi\ in[/tex]

To convert rev to in, multiply by 16π

[tex]60\ \frac{rev}{min}=60(16\pi)=960\pi\ \frac{in}{min}[/tex]