A004) Planetary Nebula/White Dwarf Stars - Little Ghost Nebula. Some red giant stars develop into planetary nebulas as their cores continue to contract, to increase in temperature, and to burn and vent the remaining gases into interstellar space. Eventually, the core collapses to the point where it is hot enough to ionize the vented gases, forming a relatively short-lived (~10,000-20,000 years) planetary nebula. The remaining core collapses into a white dwarf star. The vented materials from the planetary nebula play an important role in enriching the universe in elements with atomic weights less than 26 (forming the basis for carbon-based life like ourselves!). Which type of star will form a planetary nebula

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)