Arabbit runs across a parking lot on which a set of coordinate axis has strangely enough been drawn on coordinate system. the rabbit's path is such that the component of its position with respect to an origin of coordinate are given by the function of time by x=-0.31t^2+7.2t+28 and y=0.22t^2-9.1t+30. the rabbit's position vector r is r(t) =x(t) i+y(t) j. what are the magnitude and direction of the rabbit's position vector at t=15s

How would you place two electrons on a sphere of radius r so that the electrostatic potential energy is minimized. how would you place three electrons to solve the same problem.

Considering only the earth's rotation, determine how much later the asteroid would have had to arrive to put the explosion above helsinki at longitude 25˚ e? this would have obliterated the city.

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?