A hiker is at the bottom of a canyon facing the canyon wall closest to her. She shouts something and hears her echo 1.2 seconds later. If the sound wave travels at a speed of 340 m/s, how far away is the canyon wall in meters? (hint: to hear an echo the sound wave has to travel there and back)

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

What happens when a rubber rod is rubbed with a piece of fur?

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?