Astronomy Unit 1.3 - Measurements of the Sun

What is an arcsecond?

• 1/360 of a degree

• 1/3600 of a degree

• 1/60 of a degree

• 1/600 of a degree

What is a black body in astronomical terms?

• A type of star

• A perfect reflector of all wavelengths of radiation

• A perfect emitter and absorber of all wavelengths of radiation

• A dark region of space

What does the Astronomical Unit (AU) represent?

• The distance from the Earth to the Moon

• The distance from the Earth to the Sun at its closest point

• The average distance between the Earth and the Sun

• The distance from the Earth to the edge of the Solar System

How did Eratosthenes estimate the circumference of the Earth?

• By measuring the distance between two cities

• By measuring the angle of a shadow in one city and the distance to where the sun was directly overhead

• By calculating the distance the Earth travels in one day

How is the size of the Sun determined?

• By measuring the temperature of the Sun's core

• By calculating the distance from the Earth to the Sun

• By using the size of an AU and the proportion of the sky the Sun occupies in arcseconds

• By observing the Sun's diameter during a solar eclipse

What does the temperature of the Sun, found using the spectrum of black body radiation, indicate?

• The age of the Sun

• The size of the Sun

• The distance of the Sun from Earth

• The radiation emitted by the Sun depending only on its temperature

The graph shows how the intensity of different wavelengths of radiation from a hot object varies with temperature. What can NOT be concluded from the graph about how the distribution of the intensity of radiation from an object changes as the temperature of the object increases?

• the intensity of every wavelength increases

• the shorter the wavelength the more rapid the increase in intensity

• the peak intensity occurs at shorter wavelength

• the intensity of every wavelength decreases

In order of most to least penetrating radiation we have

• Alpha , Beta,  Gamma
• Beta , Gamma , Alpha
• Gamma, Beta, Alpha
• Gamma, Alpha, Beta

What is matter?

• Anything that has mass and volume
• The shape of an object
• How much an object weighs
• The pull of objects on one another

Emission spectra (bright line spectra) are created when electrons move from ___.

• higher to lower energy levels.

• lower to higher energy levels.

• s orbitals to p orbitals.

• one atom to a different atom.