Speed of a CD

[happylagirl]

Please help with the following problem. I'm having a hard time figuring out how to set up the problem.

"A CD, when played in a CD player, rotates at 300 rmp (meaning one revolution takes 1/300 minute). Find the average speed of a point 2 inches from the center of the CD in miles per hour."

 

[Ishuda]

Please help with the following problem. I'm having a hard time figuring out how to set up the problem.

"A CD, when played in a CD player, rotates at 300 rmp (meaning one revolution takes 1/300 minute). Find the average speed of a point 2 inches from the center of the CD in miles per hour."

If a point is 2 inches from the center and is making revolutions, what is it's path [Hint: It is not a square]? How far does it travel in one revolution?

 

[happylagirl]

Hello, I'm not quite sure I understand how to set up the problem from the information provided.

 

[Ishuda]

Hello, I'm not quite sure I understand how to set up the problem from the information provided.

A point 2 inches from the center in going around in a circle. How far does a point on the circle travel in one revolution (what is the circumference of a circle with radius 2)?

Given that distance and the fact that the point would travel in a complete circle (one revolution) in 1/300 of a minute, how fast is the point traveling.

Now you have the speed in inches per minute, convert to miles per hour.