Two friends are carrying a crate of mass 200 kg up a flight of stairs. The crate has length 1.25 m and height 0.500 m, and its center of gravity is at its center. The stairs make a 45? angle with respect to the floor. The crate also is carried at an angle 45?, so that its bottom side is parallel to the slope of the stairs. The force each person applies is vertical.

A) What is the magnitude of the upper person's force?
B) What is the magnitude of the force applied by the bottom person?
C) Is it best to be the person above or below on the stairs?

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?