VIOLENT UNIVERSE EXAM COMBINED
QUESTIONS WITH 100% VERIFIED
ANSWERS
Explain the difference between mass and weight. - ANSWER mass - the
amount of matter in an object; mass does not change
weight - a measurement of the force which acts upon an object; weight will
change depending on the gravitational pull
What is a lightyear? - ANSWER A lightyear is a unit of distance; it is equal to
the distance that light can travel in one year.
What is momentum? - ANSWER Momentum is a force that relies on the (mass
x velocity) of an object. (mass in motion is another way it can be referred to).
Why are there two high tides per day on Earth? - ANSWER The Moon's
gravity pulls on the Earth and the water on it, but the force of the Moon's
gravity varies across of the Earth. The pull is greater on the side facing the
Moon, pulling the water there closer to the Moon, while the pull is weaker on
the side away from the Moon, making the water there lag behind. This stretches
out the Earth and the water on it, creating two bulges. Remember that both the
Earth and the Moon are falling towards each other. The reason why they don't
collide, is that they already have a motion perpendicular to the direction in
which they are falling, so the falling only results in a change in that direction.
Explain any one of Newton's laws and give an example. - ANSWER Newton's
First Law states that an object will remain at rest or in uniform motion in a
straight line unless acted upon by an external force. A soccer ball will not move
unless a player kicks it.
Write down the equation of gravity and explain what each of the variables
represents. - ANSWER Fg = G *m1m2/r^2; Fg is the gravitational force; m1
,and m2 are the masses of the two objects; r is the separation between the
objects; G is the universal gravitational constant
What happens to the force of gravity if the distance between the two objects
increases? - ANSWER As two objects are separated from each other, the force
of gravitational attraction between them also decreases.
Explain conservation of angular momentum. - ANSWER The law of
conservation of angular momentum states that when no external torque acts on
an object, no change of angular momentum will occur. The conservation of
angular momentum explains the angular acceleration of an ice skater as she
brings her arms and legs close to the vertical axis of rotation. By bringing part
of the mass of her body closer to the axis she decreases her body's moment of
inertia.
Name the two types of planets in our solar system and list the names of the
planets that belong to each of the two types. - ANSWER Terrestrial planets—
Mercury, Venus, Earth, Mars
Jovian Planets—Uranus, Saturn, Jupiter, Neptune
List at least three differences between the two types of planets. - ANSWER -
jovian planets have many moons; terrestrial ones have few moons
- terrestrial planets are smaller in size and mass
- jovian planets are farther away from the sun, and farther away from each other
Why do all planets orbit the Sun in the same direction? - ANSWER The law of
conversation of angular momentum ensures that any rotating, collapsing cloud
will end up as a spinning disk. The cloud of gas (Nebula) that our solar system
originated from must have had an angular momentum. Therefore, the gas
flattened to a disk perpendicular to the axis of the spin. Since the flattened gas
disk created planets by themselves, the angular momentum was kept.
Why and how are planets inside of the frost line different from those outside the
frost line in our solar system? - ANSWER Within the frost line, rocks and
metals condense, hydrogen compounds stay gaseous. Beyond the frost line,
hydrogen compounds, rocks and metals condense. Inside the frost line, only
metal and rock could condense into solid seeds, which is why the terrestrial
planets ended up being made of metal and rock. Beyond the frost line, where it
,was cold enough for hydrogen compounds to condense into ices, the solid seeds
were built of ice along with metal and rock.
Explain why the planetesimals beyond the frost line were initially able to grow
larger than those inside the frost line. - ANSWER The planetesimals grew
largely at first (terrestrial), but then gravitational encounters between (smaller)
planetesimals tended to alter their orbits. As they crossed and collided at greater
speeds, they became more destructive. Planetesimals were shattered rather than
enlarged. Because jovian planets have large masses, the planetesimals had
gravity strong enough to capture some of the hydrogen and helium gas that
made up the vast majority of the surrounding solar nebula. This added gas made
their gravity even stronger, allowing them to capture ever more gas.
Why didn't the terrestrial planets acquire a thick atmosphere of H and He gas? -
ANSWER Radiation pressure from the sun blew most of the hydrogen and
helium beyond the frost line. The masses of the terrestrial planets were too
small.
What are the main two types of objects in the solar system that may collide with
the Earth? - ANSWER The two main types of objects that may collide with the
Earth are asteroids and comets.
a) Where do comets spend most of their lives? b) What do they look like when
they are at that location? - ANSWER Comets spend most of their time in the
outer solar system, beyond the frost line. Comets look like dirty snowballs (ice
mixed with rock and dust). They do not have tails until they get closer.
What are meteor showers and what is their origin? - ANSWER A meteor is a
space rock—or meteoroid—that enters Earth's atmosphere. As the space rock
falls toward Earth, the resistance—or drag—of the air on the rock makes it
extremely hot. What we see is a "shooting star." That bright streak is not
actually the rock, but rather the glowing hot air as the hot rock zips through the
atmosphere. When Earth encounters many meteoroids at once, we call it a
meteor shower. Meteor Showers - During certain times of the year, the Earth's
orbit passes through a belt of high concentration of cosmic dust and other
particles, and many meteors are observed.
The meteors are originated from rock debris in the Asteroid Belt.
, How large does a meteorite that hits the earth have to be to cause a global
catastrophe? - ANSWER A collision with a more than 1 km meteorite would
have severe, global consequences mostly due to debris:
- prolonged darkness and global temperature drop
- very acidic rain
- temporary heating of the atmosphere
- may cause extinctions
Google it or look it up in the textbook: What was the Tunguska event? -
ANSWER Tunguska event - is believed to have been caused by an incoming
meteor or comet, which never actually struck Earth but instead exploded in the
atmosphere, causing what is known as an air burst, three to six miles (5-10
kilometers) above Earth's surface. No impact crater has been found. The
explosion over the sparsely populated Eastern Siberian Taiga flattened 2,000
km2 (770 sq mi) of forest. It is considered the largest impact event on Earth in
recorded history. (siberia) heated to a point where it exploded 5 km above the
surface
What happened in Chelyabinsk, Russia, on February 15, 2013? - ANSWER
Largest impact in the last 100 years and the best documented event. 40,000
mph, 15 km above surface, about 20 meter meteorite, tracked how fast it was
going. The Chelyabinsk meteor was a superbolide caused by a near-Earth
asteroid that entered Earth's atmosphere over Russia on 15 February 2013 at
about 09:20 YEKT (03:20 UTC), with a speed of 19.16 ± 0.15 kilometres per
second (60,000[5]-69,000 km/h or 40,000[5]-42,900 mph).[6][7] It quickly
became a brilliant superbolide meteor over the southern Ural region. The light
from the meteor was brighter than the Sun, up to 100 km away.
What is NASA's Near Earth Object (NEO) project? - ANSWER The purpose of
the Near-Earth Object Program is to coordinate NASA-sponsored efforts to
detect, track and characterize potentially hazardous asteroids and comets that
could approach the Earth. With over 90% of the near-Earth objects larger than
one kilometer already discovered, the NEO Program is now focusing on finding
90% of the NEO population larger than 140 meters. In addition to managing the
detection and cataloging of Near-Earth objects, the NEO Program office will be
responsible for facilitating communications between the astronomical
QUESTIONS WITH 100% VERIFIED
ANSWERS
Explain the difference between mass and weight. - ANSWER mass - the
amount of matter in an object; mass does not change
weight - a measurement of the force which acts upon an object; weight will
change depending on the gravitational pull
What is a lightyear? - ANSWER A lightyear is a unit of distance; it is equal to
the distance that light can travel in one year.
What is momentum? - ANSWER Momentum is a force that relies on the (mass
x velocity) of an object. (mass in motion is another way it can be referred to).
Why are there two high tides per day on Earth? - ANSWER The Moon's
gravity pulls on the Earth and the water on it, but the force of the Moon's
gravity varies across of the Earth. The pull is greater on the side facing the
Moon, pulling the water there closer to the Moon, while the pull is weaker on
the side away from the Moon, making the water there lag behind. This stretches
out the Earth and the water on it, creating two bulges. Remember that both the
Earth and the Moon are falling towards each other. The reason why they don't
collide, is that they already have a motion perpendicular to the direction in
which they are falling, so the falling only results in a change in that direction.
Explain any one of Newton's laws and give an example. - ANSWER Newton's
First Law states that an object will remain at rest or in uniform motion in a
straight line unless acted upon by an external force. A soccer ball will not move
unless a player kicks it.
Write down the equation of gravity and explain what each of the variables
represents. - ANSWER Fg = G *m1m2/r^2; Fg is the gravitational force; m1
,and m2 are the masses of the two objects; r is the separation between the
objects; G is the universal gravitational constant
What happens to the force of gravity if the distance between the two objects
increases? - ANSWER As two objects are separated from each other, the force
of gravitational attraction between them also decreases.
Explain conservation of angular momentum. - ANSWER The law of
conservation of angular momentum states that when no external torque acts on
an object, no change of angular momentum will occur. The conservation of
angular momentum explains the angular acceleration of an ice skater as she
brings her arms and legs close to the vertical axis of rotation. By bringing part
of the mass of her body closer to the axis she decreases her body's moment of
inertia.
Name the two types of planets in our solar system and list the names of the
planets that belong to each of the two types. - ANSWER Terrestrial planets—
Mercury, Venus, Earth, Mars
Jovian Planets—Uranus, Saturn, Jupiter, Neptune
List at least three differences between the two types of planets. - ANSWER -
jovian planets have many moons; terrestrial ones have few moons
- terrestrial planets are smaller in size and mass
- jovian planets are farther away from the sun, and farther away from each other
Why do all planets orbit the Sun in the same direction? - ANSWER The law of
conversation of angular momentum ensures that any rotating, collapsing cloud
will end up as a spinning disk. The cloud of gas (Nebula) that our solar system
originated from must have had an angular momentum. Therefore, the gas
flattened to a disk perpendicular to the axis of the spin. Since the flattened gas
disk created planets by themselves, the angular momentum was kept.
Why and how are planets inside of the frost line different from those outside the
frost line in our solar system? - ANSWER Within the frost line, rocks and
metals condense, hydrogen compounds stay gaseous. Beyond the frost line,
hydrogen compounds, rocks and metals condense. Inside the frost line, only
metal and rock could condense into solid seeds, which is why the terrestrial
planets ended up being made of metal and rock. Beyond the frost line, where it
,was cold enough for hydrogen compounds to condense into ices, the solid seeds
were built of ice along with metal and rock.
Explain why the planetesimals beyond the frost line were initially able to grow
larger than those inside the frost line. - ANSWER The planetesimals grew
largely at first (terrestrial), but then gravitational encounters between (smaller)
planetesimals tended to alter their orbits. As they crossed and collided at greater
speeds, they became more destructive. Planetesimals were shattered rather than
enlarged. Because jovian planets have large masses, the planetesimals had
gravity strong enough to capture some of the hydrogen and helium gas that
made up the vast majority of the surrounding solar nebula. This added gas made
their gravity even stronger, allowing them to capture ever more gas.
Why didn't the terrestrial planets acquire a thick atmosphere of H and He gas? -
ANSWER Radiation pressure from the sun blew most of the hydrogen and
helium beyond the frost line. The masses of the terrestrial planets were too
small.
What are the main two types of objects in the solar system that may collide with
the Earth? - ANSWER The two main types of objects that may collide with the
Earth are asteroids and comets.
a) Where do comets spend most of their lives? b) What do they look like when
they are at that location? - ANSWER Comets spend most of their time in the
outer solar system, beyond the frost line. Comets look like dirty snowballs (ice
mixed with rock and dust). They do not have tails until they get closer.
What are meteor showers and what is their origin? - ANSWER A meteor is a
space rock—or meteoroid—that enters Earth's atmosphere. As the space rock
falls toward Earth, the resistance—or drag—of the air on the rock makes it
extremely hot. What we see is a "shooting star." That bright streak is not
actually the rock, but rather the glowing hot air as the hot rock zips through the
atmosphere. When Earth encounters many meteoroids at once, we call it a
meteor shower. Meteor Showers - During certain times of the year, the Earth's
orbit passes through a belt of high concentration of cosmic dust and other
particles, and many meteors are observed.
The meteors are originated from rock debris in the Asteroid Belt.
, How large does a meteorite that hits the earth have to be to cause a global
catastrophe? - ANSWER A collision with a more than 1 km meteorite would
have severe, global consequences mostly due to debris:
- prolonged darkness and global temperature drop
- very acidic rain
- temporary heating of the atmosphere
- may cause extinctions
Google it or look it up in the textbook: What was the Tunguska event? -
ANSWER Tunguska event - is believed to have been caused by an incoming
meteor or comet, which never actually struck Earth but instead exploded in the
atmosphere, causing what is known as an air burst, three to six miles (5-10
kilometers) above Earth's surface. No impact crater has been found. The
explosion over the sparsely populated Eastern Siberian Taiga flattened 2,000
km2 (770 sq mi) of forest. It is considered the largest impact event on Earth in
recorded history. (siberia) heated to a point where it exploded 5 km above the
surface
What happened in Chelyabinsk, Russia, on February 15, 2013? - ANSWER
Largest impact in the last 100 years and the best documented event. 40,000
mph, 15 km above surface, about 20 meter meteorite, tracked how fast it was
going. The Chelyabinsk meteor was a superbolide caused by a near-Earth
asteroid that entered Earth's atmosphere over Russia on 15 February 2013 at
about 09:20 YEKT (03:20 UTC), with a speed of 19.16 ± 0.15 kilometres per
second (60,000[5]-69,000 km/h or 40,000[5]-42,900 mph).[6][7] It quickly
became a brilliant superbolide meteor over the southern Ural region. The light
from the meteor was brighter than the Sun, up to 100 km away.
What is NASA's Near Earth Object (NEO) project? - ANSWER The purpose of
the Near-Earth Object Program is to coordinate NASA-sponsored efforts to
detect, track and characterize potentially hazardous asteroids and comets that
could approach the Earth. With over 90% of the near-Earth objects larger than
one kilometer already discovered, the NEO Program is now focusing on finding
90% of the NEO population larger than 140 meters. In addition to managing the
detection and cataloging of Near-Earth objects, the NEO Program office will be
responsible for facilitating communications between the astronomical
