Posted by BatBoy (24.32.124.30) on November 26, 2003 at 17:55:22:
In Reply to: science-motion posted by Thifiya on November 25, 2003 at 17:48:30:
To answer your question,
: HOw do you think an object would behave if it was pushed the same amount on opposite sides?
Based on Newton’s Three Laws of Motion..
1. Forces cause accelerations. The acceleration of an object is proportional to the ‘net' applied
force acting on it. The net force is the vector sum of all the forces acting on the object.
2. Constant velocity motion, also called uniform motion, is considered ‘natural' and does not
need to be explained. (‘Rest' is the special case of zero magnitude velocity.) In other words,
forces are not needed to explain velocities; constant velocity is not caused by a net force.
Instead, for an object to move with constant velocity, the net force on the object must be
zero. This is the essence of Newton's First Law of Motion.
3. Mass is the property of matter that resists the action of a force. Another word used to
describe this property of an object is inertia. The acceleration of an object is inversely
proportional to the mass for a constant force and is proportional to the magnitude of the
applied force. This is Newton's Second Law of Motion, and may be expressed by the
equation
F = ma
where F is the net force, m is the mass of the object, and a is the acceleration of the object.
The direction of the acceleration must be in the direction of the net force.
4. Forces always come in pairs. The application of the force caused by one body on a second is equal in magnitude
and opposite in direction to the force caused by the second body on the
first. This is Newton's Third Law of Motion.
5. Newton’s Second Law of Motion applies to all the forces acting on a single object.
Newton’s Third Law of Motion applies to the interacting forces between two objects.
6. Forces exist independently of the accelerations that they cause; in other words, force is not
defined as the product of mass and acceleration. Forces can be acting in situations where
there are no accelerations, but if an object is accelerating, then there must be at least one
external force acting on it.
: Every part of the surface of a round ball is the same. Why do you think most ball games use round balls?
: Baseball players change a ball's motion as they play. What else changes the motion of the ball during the game?
: HOw do you think an object would behave if it was pushed the same amount on opposite sides?