ASTRO (Science) EXAM 2 FINAL EXAM
QUESTIONS CORRECTLY ANSWERED.
Calculate the escape velocity from the Sun, given that its mass is 2.0 × 1030 kg
and its radius is 7.0 × 108 meters.
Vesc =
617.506
km/s
A good baseball pitcher can throw a ball at 98 miles/hour (about 43.8
meters/sec). If the pitcher were on the fictional asteroid Cochise, could the
pitcher throw the ball fast enough so it would escape from Cochise? Assume
Cochise is a sphere and that its mass is M = 8.60 × 1016 kg and its radius is 12
km = 1.20 × 104 meters.
The escape velocity equals
30.9
m/s, which is smaller than the speed of the pitch. Thus the ball can escape.
Which of the following spectra will result from a hot tenuous gas?
Emission lines characteristic of the atoms/molecules in the gas
What determines the identity of a chemical element?
The total charge of the nucleus.
The wavelength of red light is the wavelength of blue light.
Longer than
Blue light has a than red light.
higher frequency
Which kind of light travels fastest?
They all travel at the same speed.
An astronomer finds that the visible spectrum of a mysterious object shows
bright emission lines. What can she conclude about the source?
, It contains hot, relatively tenuous gas.
Most stars have spectra showing dark lines against a continuous background of
color. This observation indicates that these stars
have a hot interior that shines through cooler, low-density gas.
How do we know that the Sun contains hydrogen?
Because the Sun's spectrum contains absorption lines that match the spectrum of
hydrogen
Suppose we detect red photons at 668 nanometers emitted by electrons
dropping from the n = 3 to n = 2 orbital in hydrogen. The hydrogen is in an
interstellar cloud at 5,000 K. If the cloud were heated to 10,000 K, what would
be the wavelength of the photons emitted by the transition?
668 nm
Mars completes one orbit around the Sun in approximately two Earth years.
Mars orbits at an average distance to the Sun of about 1.5 AU, and Mars' mass
is about 1/10 of the Earth's mass. Therefore, Mars' orbital speed is the orbital
speed of the Earth
Lower than
Suppose that a planet was discovered that has twice the mass and twice the
diameter of
the Earth. What would be the escape velocity at the surface of the planet?
(Assume that
for Earth the escape velocity is 11 km/s.)
11 km/s
The planet Wozzle has the same radius as the Earth but is made out of lead, so
it is 10
times more massive than the Earth. Where would you weigh more?
Wozzle
Star A is blue, Star B is yellow, and Star C is red. Which one of these is the
hottest star?
star A
QUESTIONS CORRECTLY ANSWERED.
Calculate the escape velocity from the Sun, given that its mass is 2.0 × 1030 kg
and its radius is 7.0 × 108 meters.
Vesc =
617.506
km/s
A good baseball pitcher can throw a ball at 98 miles/hour (about 43.8
meters/sec). If the pitcher were on the fictional asteroid Cochise, could the
pitcher throw the ball fast enough so it would escape from Cochise? Assume
Cochise is a sphere and that its mass is M = 8.60 × 1016 kg and its radius is 12
km = 1.20 × 104 meters.
The escape velocity equals
30.9
m/s, which is smaller than the speed of the pitch. Thus the ball can escape.
Which of the following spectra will result from a hot tenuous gas?
Emission lines characteristic of the atoms/molecules in the gas
What determines the identity of a chemical element?
The total charge of the nucleus.
The wavelength of red light is the wavelength of blue light.
Longer than
Blue light has a than red light.
higher frequency
Which kind of light travels fastest?
They all travel at the same speed.
An astronomer finds that the visible spectrum of a mysterious object shows
bright emission lines. What can she conclude about the source?
, It contains hot, relatively tenuous gas.
Most stars have spectra showing dark lines against a continuous background of
color. This observation indicates that these stars
have a hot interior that shines through cooler, low-density gas.
How do we know that the Sun contains hydrogen?
Because the Sun's spectrum contains absorption lines that match the spectrum of
hydrogen
Suppose we detect red photons at 668 nanometers emitted by electrons
dropping from the n = 3 to n = 2 orbital in hydrogen. The hydrogen is in an
interstellar cloud at 5,000 K. If the cloud were heated to 10,000 K, what would
be the wavelength of the photons emitted by the transition?
668 nm
Mars completes one orbit around the Sun in approximately two Earth years.
Mars orbits at an average distance to the Sun of about 1.5 AU, and Mars' mass
is about 1/10 of the Earth's mass. Therefore, Mars' orbital speed is the orbital
speed of the Earth
Lower than
Suppose that a planet was discovered that has twice the mass and twice the
diameter of
the Earth. What would be the escape velocity at the surface of the planet?
(Assume that
for Earth the escape velocity is 11 km/s.)
11 km/s
The planet Wozzle has the same radius as the Earth but is made out of lead, so
it is 10
times more massive than the Earth. Where would you weigh more?
Wozzle
Star A is blue, Star B is yellow, and Star C is red. Which one of these is the
hottest star?
star A
