EOY 10 Exam Flashcards
State whether the graphs in Figure 7 relate to a location in the Northern or Southern hemisphere.
Northern hemisphere
State the reason for your answer to (i) above
longer days in summer, shorter days in winter/
During two months of the year, local clocks were adjusted to allow for daylight‑saving time.
Figure 7 shows that these two months were:
B March and October
State the feature of the graphs in Figure 7 that shows the effect of daylight‑saving time.
graph is not a smooth curve
On 13th September she observes the Sun with a sundial. It shows a time of 15:01.
Estimate her Mean Solar Time (MST) at this time.
MST = 14:57
MST = AST – EOT
= 15:01 - 4
Sarah then takes a further sundial reading 30 days later, on the 13th October.
She suggests that the Equation of Time for the 13th October would be +19 minutes.
Analyse the data in Figure 8 and comment on Sarah’s estimate for the Equation of Time on the 13th October
EOT would not be +19 minutes as maximum value for EOT is less than +19
To measure Apparent Solar Time accurately, a sundial must be correctly aligned.
State two ways of ensuring this.
Gnomon / shadow caster must point north
Calculate the ratio of the Moon’s current distance from the Earth to its distance when it formed.
11.2
Explain what would happen to each of the following if the Moon orbited much closer to the Earth: the tides on the Earth
Greater range between high and low tide because gravitational force of the moon is greater
Explain what would happen to each of the following if the Moon orbited much closer to the Earth: lunar phase cycle
short phase cycle because rotational period of moon around earth is shorter
Explain what would happen to each of the following if the Moon orbited much closer to the Earth: the appearance of a total solar eclipse
Corona not visible because Moon appears bigger in the sky
Calculate a value for the mean distance between the Earth and the Sun. Use the data from Figure 13 and the fact that both the Sun and the Moon have
the same apparent diameter
1.39 × 106
3470 (= 401
Which label from Figure 14 marks the position of the first umbral contact?
B 2
Which label from Figure 14 marks the position of the third umbral contact?
D 5
State one feature of the Moon’s orbit which means that lunar and solar eclipses do not occur every month.
Moon’s orbit does not lie on the ecliptic
State the time of local noon at the student’s location.
12:02
Calculate the student’s longitude.
The Equation of Time on this date was 0 minutes
0.5 degrees west
The ‘lunar distance’ method can be used to measure longitude. Which of the following measurements must be taken in this method?
The angular distance between the Moon and a
certain bright star
State the reason why the dish in a radio telescope must be made from metal
Metal reflects radio waves
Explain why the dish in this radio telescope needs to have a much larger diameter than the mirrors in the largest optical telescopes.
Radio waves have longer wavelength
Large aperture gives sufficient resolution.
Where the inward pull of gravity is balanced by outward radiation pressure
Main Sequence star
Where the inward pull of gravity is balanced by outward electron pressure
White Dwarf star
Where the inward pull of gravity is balanced by outward neutron pressure.
Neutron star
Describe what is meant by an emission nebula.
cloud of hydrogen gas and first stage in formation of a star
Explain the difference between absolute magnitude and apparent magnitude.
Apparent magnitude is measured from the star’s
actual distance
Absolute magnitude is measured from the same
distance for all stars
The star Sirius is actually 2.64pc from the Earth.
Calculate its apparent magnitude.
m = M - 5 + 5 log d d = 0.42
