Question 1

The force of gravity that an object has is directly related to its
A) inertia.
B) size.
C) mass.
D) density.

Accepted Answer

The force of gravity that an object has is directly related to its mass. This is because the more mass an object has, the more gravitational attraction it exerts.

Question 2

Two rocks (call them S and T)are a distance of 50 km from one another.Rock S has 20 times the mass of rock T.Which rock will move faster if the only force involved is their mutual gravitational attraction?
A) Rock S
B) Both rocks will move at the same speed.
C) Rock T
D) Not enough information is available to answer.

Accepted Answer

The force of gravity between two objects is directly proportional to their masses and inversely proportional to the distance between them squared. In this scenario, since rock S has 20 times the mass of rock T, it will exert a greater gravitational force on rock T than vice versa. Therefore, rock T will accelerate more towards rock S and move faster towards it.

Question 3

If Jupiter has an orbital period of 12 years,what is its average distance from the Sun?
A) 2 AU
B) 25 AU
C) 10 AU
D) 5 AU

Accepted Answer

According to Kepler's Third Law, the square of the orbital period is proportional to the cube of the semi-major axis of its orbit. For Jupiter, with an orbital period of 12 years, the average distance from the Sun is approximately 5 AU.

Question 4

Suppose an asteroid had an orbit with a semimajor axis of 4 AU.How long would it take for it to orbit once around the Sun?
A) 2 years
B) 4 years
C) 8 years
D) 16 years

Accepted Answer

The period, or time it takes for an object to orbit the Sun, can be calculated using Kepler's Third Law, which states that the square of the period is proportional to the cube of the semimajor axis. Using this formula, we can calculate the period of the asteroid's orbit:

T² = a³
T² = (4 AU)³
T² = 64 AU²
T = √(64 AU²)
T = 8 years

Therefore, the best choice is C) 8 years.

Question 5

If you travel 20 miles from home to school in 30 minutes,what is your average velocity?
A) 20 mph
B) 40 mph
C) 0.7 mph
D) 5 mph

Accepted Answer

Average velocity is determined by the displacement (change in position) divided by the time it takes to make that change. In this case, the displacement is 20 miles (assuming you end up at school) and the time is 30 minutes (or 0.5 hours).

Average velocity = displacement / time = 20 miles / 0.5 hours = 40 mph

Question 6

Kepler's third law can be expressed mathematically as
A)  .
B)  .
C)  .
D)  .

Accepted Answer

Kepler's third law states that the square of the period of any planet is proportional to the cube of the semi-major axis of its orbit. Mathematically, it can be expressed as P^2 ∝ a^3, where P is the period of the planet and a is the semi-major axis of its orbit. This equation can be rewritten as P^2 = Ka^3, where K is a constant of proportionality. The value of K depends on the units used to express the period and semi-major axis. Therefore, none of the options given in the question are correct.

Question 7

Which of the following is true about a comet that is on an elliptical orbit around the Sun?
A) The comet's speed is greatest when it is farthest from the Sun.
B) The comet's speed is greatest when it is nearest the Sun.
C) This comet's speed is zero.
D) The comet's speed is constant because its mass and the Sun's mass stay approximately the same.

Accepted Answer

According to Kepler's second law, a comet moves faster when it is closer to the Sun and slower when it is farther away. This means that the comet's speed is greatest when it is nearest the Sun, so the correct choice is B.

Question 8

The natural tendency of an object to resist changes in motion is called
A) inertia.
B) weight.
C) acceleration.
D) mass.

Accepted Answer

Inertia is the property of matter that causes objects to resist changes in their state of motion.

Question 9

You apply a force of 10 N to a grocery cart in order to get an acceleration of  .If you apply a force of 20 N to the same grocery cart,its acceleration will be
A)  .
B)  .
C)  .
D)  .

Accepted Answer

According to Newton's second law, force is directly proportional to acceleration. So, if you double the force, you should double the acceleration. Therefore, with 20 N of force, the acceleration will be 22eaa3e3_41a5_7f49_a4ea_7d3990bbc4b2_TB4068_11 .

Question 10

Which of the following properties of an astronaut changes when he/she is standing on the Moon,relative to when the astronaut is standing on Earth?
A) Weight
B) Mass
C) Inertia
D) All of the above

Accepted Answer

When an astronaut is standing on the Moon, the gravitational force acting on him/her is much weaker than on Earth. As weight is the measure of the force of gravity acting on an object, it changes for the astronaut standing on the Moon. However, the astronaut's mass and inertia (the tendency of an object to resist changes in motion) remain the same, as these are properties that depend on the amount of matter an object contains, which does not change.

Question 11

If a 100-kg astronaut pushes on a 5,000-kg satellite and the satellite experiences an acceleration of  ,what is the acceleration experienced by the astronaut in the opposite direction?
A) 
B) 
C) 
D)

Accepted Answer

The answer of If a 100-kg astronaut pushes on a...

Question 12

Who of the following was NOT a proponent of the heliocentric model of the solar system?
A) Galileo
B) Copernicus
C) Newton
D) Ptolemy

Accepted Answer

Ptolemy was actually a proponent of the geocentric model of the solar system, which placed Earth at the center rather than the sun. Galileo, Copernicus, and Newton were all proponents of the heliocentric model.

Question 13

Kepler's third law is a relationship between an orbiting object's
A) gravitational force and mass.
B) acceleration and mass.
C) velocity and period.
D) period and semimajor axis.

Accepted Answer

Kepler's third law relates an orbiting object's period (how long it takes to complete one orbit) to its semimajor axis (the longest radius of its elliptical orbit). It states that the square of the period is proportional to the cube of the semimajor axis. This relationship does not involve gravitational force or mass, acceleration, or velocity.

Question 14

If an object is moving in a circular orbit at a constant speed,which of the following is FALSE?
A) Its acceleration is not zero.
B) Its acceleration is zero.
C) Its velocity is not zero.
D) There is an unbalanced force acting on it.

Accepted Answer

An object moving in a circular orbit at a constant speed has a centripetal acceleration directed towards the center of the circle, so its acceleration is not zero.

Question 15

Newton's first law states that objects in motion
A) eventually come to rest.
B) experience an unbalanced force.
C) experience a nonzero acceleration.
D) stay in motion.

Accepted Answer

Newton's first law, also known as the law of inertia, states that an object at rest will stay at rest and an object in motion will stay in motion with a constant velocity unless acted upon by an external force. Therefore, the correct choice is D, stating that objects in motion stay in motion.

Question 16

The average distance between a planet and the Sun is given by the __________ of its elliptical orbit.
A) radius
B) minor axis
C) eccentricity
D) semimajor axis

Accepted Answer

The semimajor axis is the longest radius of an ellipse, which is the average distance between a planet and the Sun. Therefore, D is the best choice.

Question 17

The time it takes a planet to complete one full orbital revolution is commonly known as its
A) period.
B) frequency.
C) orbital domain.
D) velocity.

Accepted Answer

The time it takes a planet to complete one full orbital revolution is known as its period. This is a measure of time and is usually measured in Earth years. Frequency is a measure of how often a repeating event occurs, and is usually measured in hertz (Hz). Orbital domain and velocity are not measures of time specifically related to a planet's orbital revolution.

Question 18

__________ hypothesized that planetary motions could be explained by a force arising from the attraction between the mass of the planet and Sun that decreased with the square of the distance between them.
A) Johannes Kepler
B) Isaac Newton
C) Tycho Brahe
D) Nicholas Copernicus

Accepted Answer

This is a description of Newton's Law of Universal Gravitation. Kepler discovered the laws of planetary motion but did not propose a force to explain them. Brahe was an astronomer who collected data on planetary motion but did not propose a force to explain it. Copernicus proposed a heliocentric model of the solar system but did not propose a force to explain planetary motion.

Question 19

What is your acceleration if you go from 0 to 60 mph in 4 seconds?
A) 60 mph/s
B) 30 mph/s
C) 15 mph/s
D) 8.5 mph/s

Accepted Answer

Acceleration is calculated as the change in velocity divided by the time taken. Here, the change in velocity is 60 mph, and the time is 4 seconds. So, acceleration = 60 mph / 4 s = 15 mph/s.

Question 20

In a spaceship orbiting Earth,two astronauts want to measure the mass of a mouse.How can they easily do it if they are in constant free fall?
A) Place the mouse on a spring-loaded scale and weigh it.
B) Measure the gravitational attraction between the mouse and a steel ball of known mass.
C) Drop the mouse from the top of the shuttle to its bottom.
D) Push on the mouse with a known force and measure its acceleration.

Accepted Answer

In a state of free fall, traditional weighing methods like scales won't work due to the lack of gravity. Instead, using Newton's second law (F=ma), they can push the mouse with a known force and measure its acceleration to calculate its mass.

Quiz 3: Gravity and Orbitsa Celestial Ballet

The force of gravity that an object has is directly related to its

Two rocks (call them S and T) are a distance of 50 km from one another.Rock S has 20 times the mass of rock T.Which rock will move faster if the only force involved is their mutual gravitational attraction?

If Jupiter has an orbital period of 12 years,what is its average distance from the Sun?

Suppose an asteroid had an orbit with a semimajor axis of 4 AU.How long would it take for it to orbit once around the Sun?

If you travel 20 miles from home to school in 30 minutes,what is your average velocity?

Kepler's third law can be expressed mathematically as

Which of the following is true about a comet that is on an elliptical orbit around the Sun?

The natural tendency of an object to resist changes in motion is called

You apply a force of 10 N to a grocery cart in order to get an acceleration of .If you apply a force of 20 N to the same grocery cart,its acceleration will be

Which of the following properties of an astronaut changes when he/she is standing on the Moon,relative to when the astronaut is standing on Earth?

If a 100-kg astronaut pushes on a 5,000-kg satellite and the satellite experiences an acceleration of ,what is the acceleration experienced by the astronaut in the opposite direction?

Who of the following was NOT a proponent of the heliocentric model of the solar system?

Kepler's third law is a relationship between an orbiting object's

If an object is moving in a circular orbit at a constant speed,which of the following is FALSE?

Newton's first law states that objects in motion

The average distance between a planet and the Sun is given by the __________ of its elliptical orbit.

The time it takes a planet to complete one full orbital revolution is commonly known as its

__________ hypothesized that planetary motions could be explained by a force arising from the attraction between the mass of the planet and Sun that decreased with the square of the distance between them.

What is your acceleration if you go from 0 to 60 mph in 4 seconds?

In a spaceship orbiting Earth,two astronauts want to measure the mass of a mouse.How can they easily do it if they are in constant free fall?