PHY 121 Exam Questions and Answers Already Passed Latest Update 2025-2026
Hypothesis - AnswersDeals with limited evidence, but serves as a starting point for further
investigation.
Theory - Answersis a well-established body of facts that explain some aspect of nature.
We are located approximately - Answersabout 2/3 from the center of the Milky Way.
Light from the Sun takes about - Answers8 minutes to reach Earth
One of the nearest stars is Alpha Centauri, whose distance is 4.4 light-years. How long does it
take light to travel from Alpha Centauri to Earth? - Answers4.4 years
Which of the following is False?
1. A scientific theory is an undisputed fact.
2. If continual testing of a hypothesis shows it to be valid, it may become an accepted theory.
3. A hypothesis must always have one or more testable predictions. - AnswersA scientific theory
is an undisputed fact.
Approximately how many meters are in 12 feet? - Answers4
A_____becomes a _____when repeated testing of its predictinos does not disprove it.
1. Hypothesis; scientific method
2. Theory; scientific revolution
3. phenomenon; theory
4. hypthesis; theory - Answershypthesis; theory
_____is the idea that the simplest explanation for a phenomenon is usually the correct one. -
AnswersOccam's razor
Match the appropriate units one should us in each particular distance measurement.
__3__The distance between stars in our galaxy
__2__The distance between planets in our solar system
__1__The distance between cities in the US - Answers1. Kilometers
2. Astronomical Units
3. Light-years
,The language of science is - Answersmathematics
Evidence has shown that the physical laws of nature
1. Change when objects move at high speeds
2. Stay the same throughout the age of the universe.
3. depend on the mass of the objects involved.
4. are the same everywhere in the universe. - Answersare the same everywhere in the universe
A light year is measure of - Answersdistance
The Sun is part of - Answerssolar system, Milky Way Galaxy, universe - all of the above
The fact that science revolutions take place means that - Answersthe science we know now is
more correct than it was in the past.
A___is well-established idea that has been tested over and over again. - AnswersTheory
The solar sytem does not contain
1. planets
2. a star
3. Kuiper Belt objects
4. galaxies - Answersgalaxies
The largest known structure(s) in the universe is/are____ - Answersfilaments and walls
The Alpha Centauri star system is approximately 4.131 X 10^13km away from our Sun. That
equates to _______ light years. Round your answer to tfour significate firgures. (note: each light
year is about 9.46 X 10^12km) - Answers4.367
On the cosmic timeline compressed down to a single year, match each event to the
approximate month that they occur.
__3__November
__4__December 31st, evening
__2__October
__1__May - Answers1. The Milky Way forms
2. The Earth forms
, 3. Complex life develops
4. humans come into existence
How many arcseconds are in 1 degree? - Answers3600
The great Square of Pegasus is a/an - Answersasterism
Asterism - Answersa prominent pattern or group of stars, typically having a popular name but
smaller than a constellation.
The reason the Moon's synodic period is longer than its sidereal period is that - Answersthe
Moon has to catch up to the background stars
Ophiuchus - Answersis the missing sign of the Zodiac
In agient Egyptian times,____was the pole star - AnswersThuban
The strongest tides are the _____tides - Answersspring
To see the largest number of stars in one night, one would want to be at____. - Answersthe
equator
Jupiter's rotational axis is tilted 3 degrees with respect to its orbital palne. IF Earth's axis has
this tilt (rather than its 23.5 degree tilt), then the seasons on Earth would be - Answersmuch less
extreme
If the star Polaris has an altitude of 35 degrees above the northern horizon, then we know that -
Answersour latitude is +35 degrees
The meridian is definded as great circle on the sky passing through the - AnswersZenith and the
north and south celestial poles
The apparent path of the Sun across the celestial sphere during a year is called the -
Answersecliptic plane
On which day of the year does the Sun reach its northernmost point in the sky -
AnswersSummer solstice
Leap years occur because - Answersthe Earth's orbital period is 365.24 days
At approximately what time does the full Moon rise? - AnswersSunset (roughly)
The average distance beween a planet and the Sun is given by the ____of its elliptical orbit -
Answersa semimajor axis
Kepler's third law is a relationship between an orbiting object's - Answersperiod and semimajor
axis
Hypothesis - AnswersDeals with limited evidence, but serves as a starting point for further
investigation.
Theory - Answersis a well-established body of facts that explain some aspect of nature.
We are located approximately - Answersabout 2/3 from the center of the Milky Way.
Light from the Sun takes about - Answers8 minutes to reach Earth
One of the nearest stars is Alpha Centauri, whose distance is 4.4 light-years. How long does it
take light to travel from Alpha Centauri to Earth? - Answers4.4 years
Which of the following is False?
1. A scientific theory is an undisputed fact.
2. If continual testing of a hypothesis shows it to be valid, it may become an accepted theory.
3. A hypothesis must always have one or more testable predictions. - AnswersA scientific theory
is an undisputed fact.
Approximately how many meters are in 12 feet? - Answers4
A_____becomes a _____when repeated testing of its predictinos does not disprove it.
1. Hypothesis; scientific method
2. Theory; scientific revolution
3. phenomenon; theory
4. hypthesis; theory - Answershypthesis; theory
_____is the idea that the simplest explanation for a phenomenon is usually the correct one. -
AnswersOccam's razor
Match the appropriate units one should us in each particular distance measurement.
__3__The distance between stars in our galaxy
__2__The distance between planets in our solar system
__1__The distance between cities in the US - Answers1. Kilometers
2. Astronomical Units
3. Light-years
,The language of science is - Answersmathematics
Evidence has shown that the physical laws of nature
1. Change when objects move at high speeds
2. Stay the same throughout the age of the universe.
3. depend on the mass of the objects involved.
4. are the same everywhere in the universe. - Answersare the same everywhere in the universe
A light year is measure of - Answersdistance
The Sun is part of - Answerssolar system, Milky Way Galaxy, universe - all of the above
The fact that science revolutions take place means that - Answersthe science we know now is
more correct than it was in the past.
A___is well-established idea that has been tested over and over again. - AnswersTheory
The solar sytem does not contain
1. planets
2. a star
3. Kuiper Belt objects
4. galaxies - Answersgalaxies
The largest known structure(s) in the universe is/are____ - Answersfilaments and walls
The Alpha Centauri star system is approximately 4.131 X 10^13km away from our Sun. That
equates to _______ light years. Round your answer to tfour significate firgures. (note: each light
year is about 9.46 X 10^12km) - Answers4.367
On the cosmic timeline compressed down to a single year, match each event to the
approximate month that they occur.
__3__November
__4__December 31st, evening
__2__October
__1__May - Answers1. The Milky Way forms
2. The Earth forms
, 3. Complex life develops
4. humans come into existence
How many arcseconds are in 1 degree? - Answers3600
The great Square of Pegasus is a/an - Answersasterism
Asterism - Answersa prominent pattern or group of stars, typically having a popular name but
smaller than a constellation.
The reason the Moon's synodic period is longer than its sidereal period is that - Answersthe
Moon has to catch up to the background stars
Ophiuchus - Answersis the missing sign of the Zodiac
In agient Egyptian times,____was the pole star - AnswersThuban
The strongest tides are the _____tides - Answersspring
To see the largest number of stars in one night, one would want to be at____. - Answersthe
equator
Jupiter's rotational axis is tilted 3 degrees with respect to its orbital palne. IF Earth's axis has
this tilt (rather than its 23.5 degree tilt), then the seasons on Earth would be - Answersmuch less
extreme
If the star Polaris has an altitude of 35 degrees above the northern horizon, then we know that -
Answersour latitude is +35 degrees
The meridian is definded as great circle on the sky passing through the - AnswersZenith and the
north and south celestial poles
The apparent path of the Sun across the celestial sphere during a year is called the -
Answersecliptic plane
On which day of the year does the Sun reach its northernmost point in the sky -
AnswersSummer solstice
Leap years occur because - Answersthe Earth's orbital period is 365.24 days
At approximately what time does the full Moon rise? - AnswersSunset (roughly)
The average distance beween a planet and the Sun is given by the ____of its elliptical orbit -
Answersa semimajor axis
Kepler's third law is a relationship between an orbiting object's - Answersperiod and semimajor
axis
