Which of these is the likely progenitor of a type II supernova?
A) a mass-transfer binary, with the white dwarf already at 1.3 solar masses
B) a contact binary, with the neutron star at 2.3 solar masses
C) an evolved red giant which is just starting to make silicon in its core
D) two white dwarfs in a contact binary system
E) an evolved blue supergiant that is about to experience the helium flash
C
You might also like to view...
The circuit below contains 4 100-W light bulbs. The emf is 110 V. Which light bulb(s) is(are) brightest?
a.
A
b.
B
c.
C
d.
D
e.
C and D
Which of the following is not one of the most common nonsilicate groups of minerals?
a. Sulfides b. Oxides c. Chlorides d. Carbonates
Suppose you have three identical lightbulbs, some wire, and a battery. You connect one lightbulb to the battery and take note of its brightness. You add a second lightbulb, connecting it in series with the previous lightbulbs, and again take note of the brightness. Repeat the process with the third lightbulb, connecting it in series with the other two. As the lightbulbs are added, the power
delivered by the battery (neglect the battery’s internal resistance) 1.increases. 2.decreases. 3.remains the same. 4.Need more information.
The coefficients of static and kinetic friction between a 3.0-kg box and a horizontal desktop are 0.40 and 0.30, respectively. What is the force of friction on the box when a 15-N horizontal push is applied to the box?
A) 4.5 N B) 6.0 N C) 15 N D) 8.8 N E) 12 N