lesson

Updated 1 month ago Β· 7 views
If you ride on a merry-go-round, you and a friend complete one full spin in the exact same amount of time. But if your friend sits on the outer edge while you sit near the center, they will feel like they are flying through the air much faster than you.
How can two people on the same spinning ride move at completely different speeds?
Angular Speed vs. Linear Speed
To solve this puzzle, we separate motion into two ideas: how fast something rotates (angular speed) and how fast a point travels along the perimeter (linear speed).
Angular speed, written as the Greek letter Ο (omega), measures the angle rotated per unit of time: Ο=tΞΈβ.
Linear speed, written as v, measures the actual arc distance traveled per unit of time: v=tsβ, where s is the arc length.
πInteractive diagram
So how do we connect the angle turned to the distance traveled along the edge?
Connecting Linear and Angular Speed
In circular geometry, the distance along the edge of a circle, known as the arc length s, equals the radius r multiplied by the angle ΞΈ in radians: s=rΞΈ.
If we divide both sides by time t, we get tsβ=r(tΞΈβ), which gives the fundamental formula v=rΟ.
πInteractive diagram
What happens when a problem gives rotations in RPM (revolutions per minute) instead of radians per second?