Astronomy Exam 2

Suppose that you lift an object by exerting an upward force of 12 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total force on the object?

2 Newtons

Who discovered Newton's First Law of Motion?

Galileo

When Newton calculated the magnitude of the acceleration of Earth's Moon, and compared it to the acceleration of falling objects on the surface of the Earth, he found that

The Moon's acceleration was smaller

A book, weighing 10 Newtons, sits on a table. Which of the following pairs of forces is an action-reaction pair?

The force that the book exerts on the table and the force that the table exerts on the book

Galileo's approach to science is best described as based on

active construction of simplified experiments

In comparison to Kepler's Laws of Planetary Motion, Newton's theory of Universal Gravitation predicted

almost the same motions but with corrections

Once its rockets have ceased firing, an Intercontinental Ballistic Missile will follow a path that is best described as

an ellipse with the center of the Earth at one focus

Kepler's Laws

are explained by a force that attracts each planet to the Sun

Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance. If one object is twice as heavy as the other, Galileo predicted that

both objects would hit the ground at the same time

Galileo's approach to understanding moving objects was to

build things that he could measure

When Newton calculated the magnitude and direction of the acceleration for a planet that was following Kepler's Laws, he found that the magnitude of the acceleration was

inversely proportional to the square of the planet's distance from the Sun

If the acceleration of an object is zero, its speed

is not changing

According to Newton's Law of Gravity, the gravitational attraction of the Earth for other objects, such as the Moon, apples on trees and space shuttles in low earth orbit,

is smaller for objects farther from the Earth but never vanishes entirely

The planet Neptune was located because

its gravity disturbed the orbit of Uranus

Galileo said that a moving object with nothing pushing or pulling on it will always

keep moving at the same speed

Aristotle said that a moving earthly or 'mundane' object with nothing pushing or pulling on it will always

slow down and stop

When Galileo dropped a wooden ball and a heavier iron ball at the same time, he found that

sometimes the wooden ball hit first, sometimes the iron one hit first

Aristotle said that the amount of force on a moving earthly object determines its

speed

In Newton's Theory of planetary motion

the Sun and Earth move around each other

The recoil or 'kick' of a gun that is firing a bullet is a force exerted on the gun by

the bullet

According to Galileo, a thrown spear keeps moving after it has left the spear thrower's hand because

the force of friction with the air is not enough to stop the spear

According to Aristotle, a thrown spear keeps moving after it has left the spear thrower's hand because

the force of the air disturbed by the spear keeps it in motion

Suppose that you drop two objects from the same height at the same time. Both objects are heavy enough to be unaffected by air resistance. If one object is twice as heavy as the other, Aristotle would predict that

the heavier object would hit the ground long before the lighter one.

Suppose that you drop a wooden ball and an iron ball, both the exact same diameter, from the same height at the same time. Aristotle would predict that

the iron ball would hit the ground long before the wooden ball

In the ancient Greek theory of gravity, everything was attracted to the center of the universe. In Newton's theory of gravity, everything was attracted

to every other object in the universe

When Newton calculated the magnitude and direction of the acceleration of Earth's Moon, he found that the direction was

toward the Earth

When Newton calculated the magnitude and direction of the acceleration for a planet that was following Kepler's Laws, he found that the direction of the acceleration was

toward the Sun

The Law of Inertia says that if an object is not acted on by any outside force, its acceleration

will always be zero