The general principles of dynamics are rules which demonstrate a relationship between the motions of bodies and the forces which produce those motions. Based in large part on the work of his predecessors, Sir Isaac Newton deduced three laws of dynamics which he published in 1687 in his famous Princlpia.
Prior to Newton, Aristotle had established that the natural state of a body was a state of rest, and that unless a force acted upon it to maintain motion, a moving body would come to rest. Galileo had succeeded in correctly describing the behaviour of falling objects and in recording that no force was required to maintain a body in motion. He noted that the effect of force was to change motion. Huygens recognized that a change in the direction in motion involved acceleration, just as did a change in speed, and further, that the action of a force was required. Kepler deduced the laws describing the motion of planets around the sun. It was primarily from Galileo and Kepler that Newton borrowed.
1) Which of the following scientists established that the natural state of a body was a state of rest?
2) Huygen stated that accelerated was required
(A) for either a change in direction or a change in speed
(B) only for a change in speed
(C) only for a change in direction
(D) neither for a change in direction nor for a change in speed
3) The first scientist to correctly describe the behaviour of falling objects was
4) According to this passage, Newton based his laws primarily upon the work of
(A) Galileo and Copernicus
(B) Ptolemy and Copernicus
(C) Huygens and Kepler
(D) Galileo and Kepler
5) What was the main purpose of this passage?
(A) to demonstrate the development of Newton's laws
(B) to establish Newton as the authority in the field of physics
(C) to discredit Newton's laws of motion
(D) to describe the motion of planets around the sun