astronomy exam #2 module 8

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

0.001

Supposed 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?

12-10=2 Newtons

According to Aristotle, a thrown spear keeps moving after it has left the spear thrower's hand because the force of the ____ disturbed by the spear keeps it in motion.

Air disturbed by the spear keeps it in motion.

If a lighter and a heavier object were both dropped at the same time, who predicted that the heavier object would hit the ground long before the lighter one?

Aristotle

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

Both balls would always hit at exactly the same time

If a lighter and a heavier object were both dropped at the same time, who predicted that the objects would fall the same way regardless of weight?

Galileo

If the acceleration of an object is zero, its speed is doing what?

Its speed is not increasing

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

Keep moving at the same speed

Galileo's approach to understanding moving objects build things that he could _____.

Measure

Galileo's approach to science is best described as active construction of _____ experiments.

Simplified

Aristotle said that a moving earthly or 'mudane' object with nothing pushing or pulling on it will do what?

Slow down and stop

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

Sometimes the wooden ball hit first and sometimes the iron one hit first.

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

Speed

Suppose that you try to lift an object by exerting an upward force of 5 Newtons on it. If gravity exerts a force of 10 Newtons downward on the object, what is the total?

Still take the difference 5-10= -5, so 5 Newtons downward

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

The bullet

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

The exhaust from the rocket

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

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

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

The force that the book exerts on the table and the force that the table exerts on the book (it involves two objects)

Aristotle thought that the ____ object would hit the ground before the ____ object.

The heavier object before the lighter object

A horse is pulling a cart along a road. Which of the following pairs of forces is an action-reaction pair?

Two objects- The force of horse on the road and the force of the road on the horse.

If an object is moving at constant speed in a straight line, its acceleration is ____.

Zero

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

Zero