11. What is the power output of a student who completes 86 J of work in 4 seconds?

Which best represents the law of conservation of mass ?

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.