Question 1

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 2

Process of Science: Give some everyday examples that illustrate Newton's Laws of Motion.

Accepted Answer

The answer of Process of Science: Give some everyday examples...

Question 3

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

Accepted Answer

In the formula E=mc², E represents the mass-energy or potential energy stored in an object's mass. This formula describes the relationship between mass and energy and how they are interchangeable.

Question 4

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

According to Newton's Second Law of Motion, force is directly proportional to the mass and acceleration of an object. Therefore, the net force applied to an object equals its mass times acceleration.

Question 5

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

Accepted Answer

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

Question 6

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 mass and velocity, which makes option A the correct choice. It is a vector quantity that represents the amount of motion an object has.

Question 7

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 not a conserved quantity, meaning it can change during a collision. Momentum, angular momentum, and energy are all conserved quantities, meaning they remain the same before and after the collision, though they may be redistributed among the objects.

Question 8

Process of Science: Why is it not science to start with the answer to a question and look for evidence to support it?

Accepted Answer

The answer of Process of Science: Why is it not...

Question 9

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

When the ice skater pulls in his arms, he reduces his radius of rotation. According to the law of conservation of angular momentum, his angular momentum must remain constant. Since the angular momentum is the product of the velocity and the radius of rotation, and the radius is now smaller, the velocity must increase to maintain the same angular momentum. Therefore, the skater spins faster.

Question 10

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

Accepted Answer

Radiative energy is the energy carried by light, including all types of electromagnetic radiation, from radio waves to gamma rays.

Question 11

Why is Newton's version of Kepler's third law so useful to astronomers?
A)It allows us to calculate distances to distant objects.
B)It can be used to determine the masses of many 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 states that the masses of objects can be determined based on their orbital periods and distances. This is extremely useful to astronomers for determining the masses of distant objects such as planets, stars, and galaxies.

Question 12

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

Accepted Answer

Kinetic energy is the energy of motion, so this is the best choice. Potential energy is the energy an object possesses due to its position or configuration (not motion), radiative energy relates to electromagnetic waves, and mass-energy is the energy equivalent of an object's mass according to Einstein's famous equation E=mc².

Question 13

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

Accepted Answer

According to the universal law of gravitation, the gravitational force between two objects is inversely proportional to the square of the distance between them. If the distance between the objects is tripled, then the denominator in the equation becomes 9 times greater, which means the gravitational force decreases by a factor of 9.

Question 14

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 support force, which makes you feel weightless.

Question 15

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

Accepted Answer

Absolute zero is defined as the temperature at which all matter has minimal thermal energy, which is equal to 0 Kelvin or -273.15°C. It is the lowest temperature possible and cannot be achieved in practice. Choice B and C are incorrect as they refer to the Celsius and Fahrenheit scales, which do not have values that reach absolute zero. Choice D is incorrect as it refers to the boiling point of water, which is not related to absolute zero.

Question 16

The allowed shapes for the orbits of objects responding only to the force of gravity are
A)ellipses,parabolas,and hyperbolas.
B)ellipses only.
C)ellipses,spirals,and parabolas.
D)circles and ellipses.

Accepted Answer

The allowed shapes for the orbits of objects under the influence of gravity, according to Kepler's first law and Newton's law of universal gravitation, are ellipses, parabolas, and hyperbolas. Ellipses represent bound orbits, parabolas and hyperbolas represent unbound or escape orbits.

Question 17

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 general observation about the behavior of objects in gravity. The other three statements are all part of Newton's Laws of Motion.

Question 18

What is the difference between a bound orbit and an unbound orbit around the Sun?
A)A bound orbit is an orbit allowed by the universal law of gravitation,and an unbound orbit is not.
B)An object on a bound orbit has a gravitational attraction to the Sun,while an object on an unbound orbit does not.
C)A bound orbit is circular,while an unbound orbit is elliptical.
D)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.

Accepted Answer

In a bound orbit, an object is gravitationally bound to the Sun and follows the same path around it repeatedly. In an unbound orbit, an object approaches the Sun just once and then is ejected from the Solar System or follows a different path that never returns to the same point. The other choices are incorrect.

Question 19

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

On the Moon, the strength of gravity is about six times weaker than on Earth. Therefore, your weight would be less on the Moon compared to Earth, but your mass would be the same since it is an inherent property of your body and does not depend on the strength of gravity.

Question 20

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 is a scalar quantity that represents how fast an object is moving, while velocity is a vector quantity that represents both the speed and the direction of movement. Therefore, velocity includes a direction, while speed does not.

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

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?

Process of Science: Give some everyday examples that illustrate Newton's Laws of Motion.

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

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

What does temperature measure?

Momentum is defined as

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

Process of Science: Why is it not science to start with the answer to a question and look for evidence to support it?

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

Radiative energy is

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

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

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

In which of the following cases would you feel weightless?

Absolute zero is

The allowed shapes for the orbits of objects responding only to the force of gravity are

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

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

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

The difference between speed and velocity is that