Which of the following is not one of the three major strategies used to measure the mass of a galaxy cluster?
A) measuring the speeds of galaxies orbiting the cluster's center
B) studying x-ray emission from hot gas inside the cluster
C) observing how the cluster bends light from galaxies located behind it
D) measuring the temperatures of stars in the halos of the galaxies
D) measuring the temperatures of stars in the halos of the galaxies
You might also like to view...
The best way to increase the calculated fatigue-crack propagation cycles to failure of a part is
(a) To select a material with a high KIc (b) To ensure that the part has a very small initial crack length with nondestructive testing equipment. (c) To polish the surface of the part (d) To case-harden the part
Approximately how large (across) is an impact crater compared to the size of the impactor?
A) the same size B) 10—20 percent larger C) 10 times larger D) 100 times larger E) 1000 times larger
An electron has a relativistic momentum of 1.1 × 10-21 kg ? m/s. What percent of its total energy is its kinetic energy? (melectron = 9.11 ×10-31 kg, c = 3.0 × 108 m/s)
What will be an ideal response?
The rate at which work is done is equivalent to which of the following?
a. increase in potential energy c. potential energy b. thermal energy d. power