Use the image below to answer the next two questions.
Question 8
8.
Question 9
9.
Question 10
10.
Question 11
11.
Question 12
12.
Question 13
13.
Question 14
14.
Question 15
15.
The Very Large Array is a Y-shaped array of 27 identical, 25 m dishes on railway tracks. Electric cables connect the dishes. Each of the three sections of the Y is about 20km long. The VLA has a resolution as so fine that the centimetre marks on a ruler could be seen five km away- if the ruler were broadcasting radio waves!
Question 16
16.
Question 17
17.
Question 18
18.
Explain how the dark lines on absorption spectra help astronomers determine a stars composition.
Question 19
19.
Explain how a radar gun can be used to determine how fast a car is going.
Question 20
20.
Explain how astronomers use spectra to determine if a star is receding (moving away) or advancing (moving closer).
Question 21
21.
Why would the discovery of radio waves be important in determining the compostion of stars?
Question 22
22.
How might attaching radio telescopes to satellities launched into space help astronomers gain information about stars?
Match the term and its meaning
adaptive optics
astronomical unit
diffraction grating
Doppler Effect
electromagnetic radiation
interferometry
light-year
parallax
radio astonomy
radio object
spectral lines
spectral analysis
spectroscope
spectroscopy
spectrum
triangulation
dark or bright lines observed in the spectra of stars
technology that adjusts the mirror of a telescope to cancel the effects of constant changes in Earth's atmosphere
the study of spectra produced when a beam of light passes through a prism
the distance from the Earth to the Sun
varying types of energy waves emitted by stars
the apparent shift in position of a nearby object when viewed from two different points
object in space that gives off large amounts of radio waves
phenomenon where wave changes occur when an object moves toward or away from an observer
using radio waves to learn about the composition of stars
method of estimating the distance to a object by creating an imaginary triangle
a device that produces a focused spectrum
bands of side-by-side colours produced when light refracts
device with many closely spaced slits through which light passes to produce a spectrum
the distance that light travels in one year
the study of spectra
technology that combines the images of several telescopes into one
A dark line spectrum is produced when the light from
a gas heated at low temperature passes through a spectroscope
a substance heated at high temperature passes through a spectroscope.
a substance heated at high temperature passes through a cooler gas and then through a spectroscope.
a gas that is frozen and then travels through Earth's atmosphere.
When light passes through a diffraction grating,
it bends around the corners of the openings and splits into different colours
it refracts because it is travelling from a low density substance to a higher density substance.
it produces a solid band of colour instead of a spectrum.
blue and red colours are not visible.
Which of the following is the principle on which a police officer's radar gun establishes a car's speed?
The Law of Conservation of Mass
Newton's Law of Gravity
The Law of Reflection.
The Doppler Effect
In a spectrum, the light with the longest wavelengths are found
on the left.
on the right.
in the centre.
on either end.
If the spectral lines for a particular star are red-shifted, you can infer that
the star is moving closer to Earth.
the star is not moving.
the star is moving away from Earth.
the star is increasing in temperature.
From the information above, which elements appear to be present in the Sun?
hydrogen, helium, and sodium
calcium, helium, and sodium
mercury, calcium, and hydrogen
mercury, sodium, and helium
From the information above you can infer that
all three spectra were taken at the same time
from Spectrum A to Spectrum B there is a blue-shift.
from Spectrum A to Spectrum C there is a blue-shift.
from Spectrum B to Spectrum C there is a blue-shift
If Spectrum A was taken 10 years before Spectrum C, you can infer that
the star is stationary.
the star is moving closer
the star is giving off more visible light as time passes
the star is moving away
Spectra produced from radio waves tend to have poor resolution because
radio waves have very long wavelengths
radio waves are visible only in the night sky.
radio waves have very short wavelengths
radio waves are difficult to see because of interference from the Sun's rays
Martha wanted to use triangulation to estimate the distance from her to a tree in the distance. On her scale drawing she used a circle to represent where she was standing and a star to represent the tree. She then measured the angles formed by the ends of the baseline and the star. Finally, she drew a line from where she
Was standing to the tree. What serious error did Martha make?
She should have used a picture of tree and not a star
She should have written the angle measurements on her diagram
She should have drawn the line from the tree to her perpendicular to the baseline
She did not make a serious error
The diameter of Earth's orbit is used as a baseline when determining the distance to a star because
it is the most convenient.
the Earth orbits the Sun everyday
it will usually result in producing an equilateral triangle.
this measurement provides the longest baseline possible
The distant stars must be used as reference points because
of parallax
the distance between these stars may have changed.
the Earth has rotated
the distance between the nearby star and the Earth has changed
It was first determined that radio waves were being emitted by stars when
it was observed that the strongest radio waves were coming from particular places in outer space.
Karl Jansky came across a hissing noise while talking on the telephone.
scientists discovered that the Sun did not give off radio waves
scientists first observed the stars with refracting telescopes
Colour-coding of radio waves emitted by stars was done on the basis of
the type of substances emitting radio waves
the intensities of the signals
the distances to the stars
the type of radio spectroscope used
The technology described in the paragraph is
spectroscopy
triangulation.
interpolation
interferometry
Which of the following statements is true of the image created by combining the information received by the 27 dishes?
The image produced would be as large as the area covered by all the dishes
The resulting image would be as good as if one telescope were used that was as big as the area covered by all 27 dishes.
The astronomers' job is to combine the 27 images received by the dishes using a method called "cut and paste".
The resolution of the image created is still not as good as an image that would be created by a single telescope
