Question 1

Radiative energy is ________.
A) energy carried by light
B) heat energy
C) energy from nuclear power plants
D) energy of motion

Accepted Answer

Radiative energy refers to the energy associated with electromagnetic waves, including light. Therefore, the best choice is A. Heat energy (B) refers to thermal energy and is not necessarily associated with electromagnetic waves. Energy from nuclear power plants (C) refers to the energy produced through nuclear reactions. Energy of motion (D) refers to the kinetic energy of an object in motion.

Question 2

If I drop a golf ball and a bowling ball simultaneously from same height above the ground, what will happen? Neglect the effects of wind or air resistance.
A) The golf ball and the bowling ball will hit the ground at the same time.
B) The bowling ball will hit the ground before the golf ball.
C) The golf ball will hit the ground before the bowling ball.

Accepted Answer

According to Galileo's Law of Falling Bodies, objects of different masses, when dropped from the same height, will fall at the same rate and hit the ground at the same time in the absence of any air resistance. Therefore, the golf ball and the bowling ball will hit the ground at the same time.

Question 3

What is the difference between a bound orbit and an unbound orbit around the Sun?
A) An object on a bound orbit follows the same path around the Sun over and over, while an object on an unbound orbit approaches the Sun just once and then never returns.
B) A bound orbit is an orbit allowed by the universal law of gravitation, and an unbound orbit is not.
C) An object on a bound orbit has a gravitational attraction to the Sun, while an object on an unbound orbit does not.
D) A bound orbit is circular, while an unbound orbit is elliptical.

Accepted Answer

A bound orbit is one in which the object revolves around the Sun repeatedly, following the same path each time. An unbound orbit is one in which the object approaches the Sun once but does not return. This happens because it either gains enough speed from the Sun's gravity to escape it, or it is deflected by the gravity of other planets or stars.

Question 4

Suppose that two objects collide. Which of the following things is not the same both before and after the collision?
A) The total temperature of the objects
B) The total momentum of the objects
C) The total angular momentum of the objects
D) The total energy of the objects

Accepted Answer

Temperature is a measure of the average kinetic energy of the particles in an object. In a collision, the total temperature of the objects involved may remain constant or change depending on factors such as the conservation of energy and the type of collision. However, it is not a quantity that is always conserved, unlike momentum, angular momentum, and energy.

Question 5

Momentum is defined as ________.
A) mass times velocity
B) mass times speed
C) force times velocity
D) mass times acceleration

Accepted Answer

Momentum is defined as the product of an object's mass and velocity. Therefore, the correct choice is A, which states that momentum is equal to mass times velocity.

Question 6

In which of the following cases would you feel weightless?
A) While falling from a roof
B) While parachuting from an airplane
C) While accelerating downward in an elevator
D) While walking on the Moon

Accepted Answer

When falling from a roof, you are in free fall, experiencing no contact forces, which makes you feel weightless.

Question 7

In the formula E=mc², what does E represent?
A) The mass-energy, or potential energy stored in an object's mass
B) The kinetic energy of a moving object
C) The radiative energy carried by light
D) The gravitational potential energy of an object held above the ground
E) The electric field produced by a charge

Accepted Answer

In the formula E=mc², E represents the mass-energy or potential energy stored in an object's mass. It means that the energy and mass are interchangeable and can be converted into each other. The formula specifically relates the amount of energy (E) that can be obtained from a given amount of mass (m) through the conversion process.

Question 8

Absolute zero is ________.
A) 0 Kelvin
B) 0∘ Celsius
C) 0∘ Fahrenheit
D) 100∘ Celsius

Accepted Answer

Absolute zero is defined as 0 Kelvin, which is the point at which all matter has no thermal energy and cannot be further cooled. 0∘ Celsius is the freezing point of water, and 0∘ Fahrenheit is a specific temperature at which saltwater freezes. 100∘ Celsius is the boiling point of water.

Question 9

What does temperature measure?
A) The average kinetic energy of particles in a substance
B) The average mass of particles in a substance
C) The total potential energy of particles in a substance
D) The total amount of heat in a substance

Accepted Answer

Temperature measures the average kinetic energy of particles in a substance.

Question 10

Newton's Second Law of Motion tells us that the net force applied to an object equals its ________.
A) mass times acceleration
B) mass times energy
C) momentum times velocity
D) mass times velocity

Accepted Answer

Newton's Second Law of Motion states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. Mathematically, this can be represented as F=ma, where F is the net force, m is the mass of the object, and a is the acceleration it experiences. Therefore, the net force applied to an object equals its mass times acceleration.

Question 11

Why is Newton's version of Kepler's third law so useful to astronomers?
A) It can be used to determine the masses of many distant objects.
B) It allows us to calculate distances to distant objects.
C) It tells us that more-distant planets orbit the Sun more slowly.
D) It explains why objects spin faster when they shrink in size.

Accepted Answer

Newton's version of Kepler's third law relates the orbital period and distance of a planet to the mass of the central star. This makes it very useful for determining the masses of planets, moons, asteroids, and other objects in our solar system and beyond, based on their orbital periods and distances.

Question 12

According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them ________.
A) decreases by a factor of 9
B) increases by a factor of 9
C) decreases by a factor of 3
D) increases by a factor of 3

Accepted Answer

The gravitational force is inversely proportional to the square of the distance between two objects. Tripling the distance results in the force decreasing by a factor of 3^2, which is 9.

Question 13

The acceleration of gravity on Earth is approximately 10 m/s² (more precisely, 9.8 m/s²). If you drop a rock from a tall building, about how fast will it be falling after 3 seconds?
A) 30 m/s
B) 10 m/s
C) 30 m/s²
D) 10 m/s²
E) 20 m/s

Accepted Answer

The speed of the rock after 3 seconds can be calculated using the formula v = g*t, where g is the acceleration due to gravity (approximately 10 m/s²) and t is the time in seconds. So, after 3 seconds, the speed would be 10 m/s² * 3 s = 30 m/s.

Question 14

When a spinning ice skater pulls in his arms, he spins faster because ________.
A) his angular momentum must be conserved, so reducing his radius must increase his speed of rotation
B) there is less friction with the air
C) there is less friction with the ice
D) there exists an unbalanced reaction force

Accepted Answer

Angular momentum is conserved, which means the product of the skater's moment of inertia and his angular velocity must remain constant. When he pulls in his arms, his moment of inertia decreases, so his angular velocity must increase in order to conserve angular momentum. This causes him to spin faster.

Question 15

What do we mean by the orbital energy of an orbiting object (such as a planet, moon, or satellite)?
A) Orbital energy is the sum of the object's kinetic energy and its gravitational potential energy as it moves through its orbit.
B) Orbital energy is the object's kinetic energy as it moves through its orbit.
C) Orbital energy is a measure of the object's speed as it moves through its orbit.
D) Orbital energy is the amount of energy required for the object to leave orbit and escape into space.

Accepted Answer

The orbital energy of an object is the combined amount of kinetic energy and gravitational potential energy that it possesses as it moves through its orbit. Kinetic energy is determined by the object's motion, while gravitational potential energy is determined by its position in the gravitational field of the larger object it is orbiting. Therefore, since the object has both kinetic and potential energy, the best choice is A.

Question 16

The difference between speed and velocity is that ________.
A) they are expressed in different units
B) velocity also includes a direction
C) velocity is the same as acceleration but speed is different
D) velocity is calculated using a physics equation

Accepted Answer

Speed refers to the rate at which an object moves, while velocity includes both the object's speed and the direction in which it is moving. Therefore, choice B is the correct answer. Choices A, C, and D are incorrect because they do not accurately describe the difference between speed and velocity.

Question 17

The gravitational force that the Earth exerts on the Moon is equal and opposite to that which the Moon exerts on the Earth. Therefore, according to Newton's second law of motion,
A) the Moon as a larger acceleration than the Earth, because it has a smaller mass.
B) the Moon and the Earth both have equal accelerations, because the forces are equal.
C) the Earth has a larger acceleration than the Moon, because it has a larger mass.

Accepted Answer

According to Newton's second law, acceleration is inversely proportional to mass when force is constant. Since the Moon has a smaller mass, it experiences a larger acceleration.

Question 18

Which of the following statements is not one of Newton's Laws of Motion?
A) What goes up must come down.
B) The rate of change of momentum of an object is equal to the net force applied to the object.
C) In the absence of a net force acting upon it, an object moves with constant velocity.
D) For any force, there always is an equal and opposite reaction force.

Accepted Answer

"What goes up must come down" is not one of Newton's Laws of Motion. It is a common saying, but does not accurately reflect the scientific principles behind motion and gravity.

Question 19

The energy attributed to an object by virtue of its motion is known as ________.
A) kinetic energy
B) potential energy
C) radiative energy
D) mass-energy

Accepted Answer

Kinetic energy is the energy that an object possesses due to its motion. The greater the object's velocity and mass, the greater its kinetic energy. Therefore, option A is the correct answer. Option B is potential energy, which is stored energy that an object possesses due to its position or state. Option C is radiative energy which is the energy that photons carry. Option D is mass-energy, which is the energy that an object possesses due to its mass, according to Einstein's famous equation, E=mc^2.

Question 20

Suppose you lived on the Moon. Which of the following would be true?
A) Your weight would be less than your weight on Earth, but your mass would be the same as it is on Earth.
B) Both your weight and your mass would be less than they are on Earth.
C) Your mass would be less than your mass on Earth, but your weight would be the same as it is on Earth.
D) Both your weight and your mass would be the same as they are on Earth.

Accepted Answer

The gravitational pull on the Moon is weaker than it is on Earth, which would cause your weight to be less on the Moon. However, your mass would remain the same as it is an intrinsic property of an object and does not depend on the gravitational force acting on it.

Quiz 4: Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Radiative energy is ________.

If I drop a golf ball and a bowling ball simultaneously from same height above the ground, what will happen? Neglect the effects of wind or air resistance.

What is the difference between a bound orbit and an unbound orbit around the Sun?

Suppose that two objects collide. Which of the following things is not the same both before and after the collision?

Momentum is defined as ________.

In which of the following cases would you feel weightless?

In the formula E=mc², what does E represent?

Absolute zero is ________.

What does temperature measure?

Newton's Second Law of Motion tells us that the net force applied to an object equals its ________.

Why is Newton's version of Kepler's third law so useful to astronomers?

According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them ________.

The acceleration of gravity on Earth is approximately 10 m/s² (more precisely, 9.8 m/s²) . If you drop a rock from a tall building, about how fast will it be falling after 3 seconds?

When a spinning ice skater pulls in his arms, he spins faster because ________.

What do we mean by the orbital energy of an orbiting object (such as a planet, moon, or satellite) ?

The difference between speed and velocity is that ________.

The gravitational force that the Earth exerts on the Moon is equal and opposite to that which the Moon exerts on the Earth. Therefore, according to Newton's second law of motion,

Which of the following statements is not one of Newton's Laws of Motion?

The energy attributed to an object by virtue of its motion is known as ________.

Suppose you lived on the Moon. Which of the following would be true?