The magnetic field on the axis of a circular current loop is far from uniform (it falls off sharply with increasing z). you can produce a more nearly uniform field by using two such loops a distance d apart .
find the field (b) as a function of z, and show that ∂b/∂z is zero at the point midway between them (z)

Two friends are having a conversation. anna says a satellite in orbit is in freefall because the satellite keeps falling toward earth. tom says a satellite in orbit is not in freefall because the acceleration due to gravity is not 9.80 m/2 . who do you agree with and why?

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.

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?