•Q1. If a type G star like the sun expands to become a
giant star with a radius 20 times
larger, by what factor will its density decrease?
Density = mass/volume
–Mass is the same, volume of sphere = 4/3 π R3
–Radius increases
by 20, R3 and the volume increases by 203 = 8000, so density decreases
by 8000
–
•Q2. In an H-R Diagram, stars with the largest radius are
found in the upper right
of the diagram. (Fill in the blank.)
•Q3. The lifetime of high temperature main sequence O and
B stars is much shorter than the lifetime of low temperature K and M stars. (Fill in the blank.)