The force between a positively charged foam cup and a positively charged metal sphere is 5.2 × 10−4 newtons. The charge on the cup is 7.2 × 10−6 coulombs, and the charge on the metal sphere is 6.8 × 10−6 coulombs. What is the distance between the two objects? (k = 9.0 × 109 newton·meters 2/coulombs2)

It indicates no change in temperature and the process of matter changing its state

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

C. the electric current passes from the slip rings, through the brushes, and to the collection device.