Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. The
astronaut has her lucky penny in her hand behind her
back as the space pirates break into the control room.
She has just locked the controls so that the ship is
accelerating in the direction of the control room's ceiling.
Simon wants the astronaut to use the penny to hit a
button on the control panel to turn off the lights and
escape. The button is located a short distance behind
and below the astronaut's hands.

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.

Awind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. its blades are 20 m in length. (a) what is the angular acceleration of the turbine? (b) what is the centripetal acceleration of the tip of the blades at t=0s? (c) what is the magnitude and direction of the total linear acceleration of the tip of the blades at t=0s?

The particles that are found in the nucleus of an atom are