Cygnus X-1 and LMC X-3 are black holes if the masses of the unseen companions perhaps may be
a. less than 3 solar masses.
b. more than 3 solar masses.
c. between 0.4 and 1.4 solar masses.
d. less than 0.4 solar masses.
e. not larger than the masses of the stars that we can see.
Question 2
A wave on a lake is found to have a wavelength of 2 m and a frequency of 0.3 Hz. What is the speed of this wave?
What will be an ideal response?