Which of the following methods uses the principle of orbital acceleration to detect planets around another star?
A) measuring a single Doppler shift of a star, one time
B) measuring change in the Doppler shifts of a star over the course of many nights
C) taking a picture of the planet next to the star
D) measuring the change of light of a star as the planet crosses in front of it
B
You might also like to view...
It is bright everywhere. You have been able to travel around, and it's clear that you are not inside a star. Yet your surroundings seem as bright as looking directly at the Sun
As you travel around, you notice that you cannot find a single neutral atom anywhere, nor can you find any nucleus besides those of hydrogen and helium. While it is hot (a few thousand degrees Kelvin), it is nowhere near the temperature needed for nuclear fusion. Where are you? A) You are in the planetary nebula that the Sun will form about 5 billion years from now. B) You are in an accretion disk around a supermassive black hole. C) You are in the universe more than 10100 years in the future. D) You are in the universe during its first 380,000 years. E) You are in the central regions of a quasar.
The accretion disk of a black hole is typically very hot. What kind of telescope would we use to observe it at its strongest wavelength?
A. a space-based radio telescope B. a ground-based gamma-ray telescope C. a ground-based X-ray telescope D. a space-based X-ray telescope E. None of these choices are correct.
An aluminum tube (E 5 72 GPa) AB of circular cross section has a pinned support at the base and is pin-connected at the top to a horizon-tal beam supporting a load Q 5 600 kN. The outside diameter of the tube is 200 mm and the desired factor of safety with respect to Euler buck-ling is 3.0. The required thickness t of the tube is most nearly:
(A) 8 mm
(B) 10 mm
(C) 12 mm
(D) 14 mm
A circular disk is rotating about a central axis with an angular velocity which is increasing at a constant rate. Point 1 on the disk is located at a distance r1 from the center of the disk and point 2 on the disk is located at a distance r2 from the center of the disk. If r2 = 2r1, which of the following ratios is the largest? 1 and 2 refer to being at points 1 and 2 in the subscripts below, all
values occurring at the same time. a. ?2/?1 b. ?2/?1 c. ac2/ac1 d. All the ratios are 1 so none is larger.