If I attach a tennis ball to a string and swing it in a circle of radius 4.8 meters so the ball completes one revolution every 2.2 seconds, then what is the speed of the ball (number of m/s)?   The 2.2 second time to go around the circle is known as the period of the ball's motion, and the speed is often referred to as the tangential speed because the direction of its associated velocity is tangent to the circle.

A large spherical gas cloud of radius = 5 x109 km has a mass = 2.4 x1030 kg, and is spinning to make one revolution in 60 years (i.e. Earth years, each of 365 days of 24 hours each). Due to gravity, the cloud gets smaller to a radius = 1.2 x106 km. What will be its period of rotation in minutes?

A sprinter participating in the 200 m dash has to run around a track that has a circular arc with a radius of curvature of 26 m.  She completes the 200 m dash in 22.8 seconds at constant speed throughout the race. a) What is the magnitude of her centripetal acceleration in m/s2 as she runs the curved portion of the track?  b) What is the magnitude of her tangential acceleration in m/s2 as she runs the curved portion of the track?   c) What is the magnitude of her angular acceleration in rad/s2 as she runs the curved portion of the track?   d) What is the magnitude of her resultant linear acceleration in m/s2 as she runs the curved portion of the track?

A three-blade wind turbine, which spins perpendicularly to the ground, is set on a pole that is 38 m tall and completes 5 revolutions in one minute. The length of one blade is approximately 4 m long. One particular blade lies parallel to the ground before the turbine started to spin. a) What is the equation that models the height of tip of this blade as a function of time (in seconds)?