Positive electric charge Q is distributed uniformly along a thin rod of length 2a. The rod lies along the x-axis between x=−a and x=+a (Figure 1). Calculate how much work you must do to bring a positive point charge q from infinity to the point x=+L on the x-axis, where L>a. To find V, divide the rod into infinitesimal segments of length dx1. Consider one such segment located at x=x1, where −a≤x1≤a. What is the potential dV at x=+L due to this segment?

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?

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?

Which statement best describes the direction of the buoyant force on any object? a. opposite the force of gravity b. in the same direction as the weight c. in the direction of motion of the object d. opposite the direction of motion of the object