Astronomy Chapter 5 Exam

What total force will cause an object with a mass of 1kg to gain 5 meters per second every second?

5 Newtons

An ion rocket engine produces 1 Newton of thrust. What acceleration can it give to a space probe with a mass of 1000kg?

0.001 m/s²

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

Galileo predicted that dropping a wooden ball and an iron ball at exactly the same time would result in them hitting the ground at the same time, so long as air friction was negligible. When he actually did the experiment, the balls hit the ground very close together, but sometimes the wooden ball hit first and sometimes the iron one hit first. If we repeat his experiment today, we find exactly the same thing. Which of the following conclusions is appropriate?

Galileo really did the experiment

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

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

almost the same motions but with corrections

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

The International Space Station (ISS) is in a roughly circular orbit near the surface of the Earth, moving at around 5 miles per second. Suppose that a rocket pushes it and quickly increases its speed to 6 miles per second. The ISS will then

follow an ellipse that rises and then descends again

A rocket that leaves the Earth's atmosphere at a speed of 4 miles per second will

follow an elliptical path that is partly below the surface of the Earth

Freely falling objects with different masses fall with the same acceleration because

gravity exerts more force on the more massive object

The force of gravity explains

how the tides work but not how lightning works

If the acceleration of an object is zero, its speed

is not changing

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

keep moving at the same speed

The Law of Inertia states that a moving object will

keep moving if no force acts on it

A unit of mass is the

kilogram

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

slow down and stop

An artificial satellite such as the International Space Station stays up because

the Earth curves out from under it as fast as it falls

In Newton's Theory of planetary motion,

the Sun and Earth move around each other

The force that acts on a rocket because its engine is firing is exerted by

the exhaust from the rocket

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

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