An astronomer examining a compact object could conclude that it was a black hole if it _____.
a. emits regular pulses of radiation
b. has a defined event horizon that emits X-rays
c. has an accretion disk
d. has a mass greater than 1.4 solar masses
e. has a mass greater than 3 solar masses
Question 2
Which statement best describes a theory?
a. A group of ideas about how something should be done, made, or thought about
b. A specific statement about nature that needs further testing
c. An idea considered so obviously true that the idea does not need to be questioned
d. A fundamental principle in which scientists have great confidence
e. A general description of some aspect of nature that has been thoroughly tested and widely accepted
A Black cat under the snow.
Black Russian Terrier
This graphic illustrates the original systems model of politics advanced by David Easton. Politics
The coefficient of the restitution of an object is defined as the ratio of its outgoing to ...
A(n) _____ is a spur-of-the-moment question. Fill in the blank(s) with correct word