Astro 150 Exam 1 Review

Suppose an object moves in a circular path at constant speed. What can be said about any force that might be acting on it?

• There is no force acting on it

• The force acts only at the top or bottom of the circle

• The force acts towards the center of the circle

• The force acting on it must be acting in the direction opposite its motion

Mercury lies 3 times closer to the Sun than the Earth; on Earth the Suns luminosity is...

• the same

• 3x more luminous

• 1/3x as luminous

• 1/9x as luminous

Mercury lies 3 times closer to the Sun than the Earth; on Earth the Sun appears...

• 9 times brighter than on Mercury

• one ninth as bright as on Mercury

• 3 times brighter than on Mercury

• one third as bright as on Mercury

Ultraviolet light waves have _______ compared with visible electromagnetic radiation

• high energy and high frequency

• high energy and low frequency

• low energy and low frequency

• low energy and high frequency

• same energy and same frequency

Which of the following telescopes has the best resolving power?

• not enough information given to answer the question

• a 10 cm telescope in ultraviolet wavelengths

• a 10 cm telescope in optical wavelengths

• a 100 cm radio telescope observing at a wavelength of 100 meters

For which of the following reasons have solar neutrino experiments surprised scientists?

• Too few neutrinos have been detected compared to those expected from models of the Sun

• The wrong kind of solar neutrinos have been found

• No solar neutrinos have been found

• Far too many solar neutrinos have been detected

Why are neutrinos so hard to detect?

• They are electrically neutral

• They rarely interact with matter

• There are too few of them

• They are massless

The temperature of the center of the Sun is roughly

• 1,500,000 K

• 15,000,000 K

• 58,000,000 K

• 5,800 K

Pretend that all stars are the same (same size, same temperature). Suppose a 1 meter diameter telescope can barely detect one of the stars that is a certain distance away. How much farther into space could a 2 meter telescope barely detect stars?

• 1.4 times

• 2 times

• 4 times

• 8 times

Suppose we observe a cool, tenuous gas with a hot 'black body' behind it. The combined spectrum will be

• absorption lines only

• continuous spectrum with bright lines superimposed

• continuous radiation with dark lines superimposed

• emission lines only