A solid disk and a thin-walled hoop each have a diameter of 8 cm. Both are released from rest at the same time at the top of a ramp that is 175 cm high and start rolling down the incline. What is the velocity of each at the bottom of the ramp? What percentage of the gravitational potential energy has been transformed into angular kinetic energy for each? Into what form of energy is the remaining percentage transformed?

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. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?