A reference frame in which Newton's laws are valid is known as an inertial reference frame. Mass is a good measure of inertia light objects are easy to move, but heavy objects are much harder to move, and it is much harder to change their motion once they start moving.Ī good question to ask is: do Newton's laws apply all the time? In most cases they do, but if we're trying to analyze motion in an accelerated reference frame (while we're spinning around would be a good example) then Newton's law are not valid. The tendency of an object to maintain its state of motion, to remain at rest or to keep moving at a constant velocity, is known as inertia. Note that the net force is the sum of all the forces acting on an object. Newton's first law states that an object at rest tends to remain at rest, and an object in motion tends to remain in motion with a constant velocity (constant speed and direction of motion), unless it is acted on by a nonzero net force. Newton summarized Galileo's thoughts about the state of motion of an object in a statement we call Newton's first law. Galileo (1564-1642) had a better understanding of the situation, however, and realized that the Greeks weren't accounting for forces such as friction acting on the objects they observed. The ancient Greeks, guided by Aristotle (384-322 BC) in particular, thought that the natural state of motion of an object is at rest, seeing as anything they set into motion eventually came to a stop. We'll look at the three laws one at a time. These are important enough that we call them Newton's laws of motion. Isaac Newton (1642-1727) studied forces and noticed three things in particular about them. Remember that an acceleration produces a change in velocity (magnitude and/or direction), so an unbalanced force will change the velocity of an object. In other words, acceleration occurs when there is a net force, but no acceleration occurs when the forces are balanced. Acceleration occurs when there is a net force on an object no acceleration occurs when the net force (the sum of all the forces) is zero. When it hit the ground, more forces came into play to bring the ball to a stop.Ī force is an interaction between objects that tends to produce acceleration of the objects. But, how did the ball get its initial velocity in the first place? When it hit the ground, what made it eventually come to a stop? To give the ball the initial velocity, we threw it, so we applied a force to the ball. We've introduced the concept of projectile motion, and talked about throwing a ball off a cliff, analyzing the motion as it traveled through the air. Newton's laws of motion Newton's laws of motion
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |