101. Navigating in the Big Dipper. All the stars of the Big Dipper (part of the constellation Ursa Major) may appear to be the same distance from the earth, but in fact they are very far from each other. Figure $1.44$ shows the distances from the earth to each of these stars. The distances are given in light years (ly), the distance that light travels in one year.

 101. Navigating in the Big Dipper. All the stars of the Big Dipper (part of the constellation Ursa Major) may appear to be the same distance from the earth, but in fact they are very far from each other. Figure $1.44$ shows the distances from the earth to each of these stars. The distances are given in light years (ly), the distance that light travels in one year. One light year equals $9.461 \times 10^{15} \mathrm{~m}$. (a) Alkaid and Merak are $25.6^{\circ}$ apart in the earth's sky. In a diagram, show the relative positions of Alkaid, Merak, and our sun. Find the distance in light years from Alkaid to Merak. (b) To an inhabitant of a planet orbiting Merak, how many degrees apart in the sky would Alkaid and our sun be?