ppt physics.pptx for physics in college students

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1. FRAMES OF REFERENCE The frame relative to which the position or the motion of a body is specified is called the Frame of Reference. It is a coordinate system. The simple frame of reference is the cartesian coordinate system in which every point of space may be described by three numbers ( x,y,z ), the three coordinates of that point.

2. FRAME OF REFERENCE Motion of an object in relation to a fixed body or place. To describe motion accurately and completely . THE MOST COMMON FRAME OF REFERENCE : The Earth

3. TYPES OF FRAME OF REFERENCE The Frame of Reference is of two types: Inertial Frame of Reference( Unaccelerated or non-accelerated ) Non-Inertial Frame of Reference( Accelerated)

4. INERTIAL FRAME OF REFERENCE The frame of reference in which the Newton’s law holds, are called the inertial frames. According to Newton’s law, a body not acted upon by any external force, has an unaccelerated motion. In other words, if a body is at rest, it remains at rest, but if it is in motion , it remains moving with the same speed in the same direction unless an external force is applied.

5. From Newton’s Second Law of Motion:- F=ma If F=0, then ma=0 but m can’t be zero, so, a=0 Thus, Inertial Frame of Reference is also known as Unaccelerated or Non-accelerated frame of reference.

6. EXAMPLES OF INERTIAL FRAME OF REFERENCE An observer in each inertial frame has the same description of physical events. In other words the frame S and S’ are said to be inertial only if the acceleration of a body measured by the observers in both frames is same. Consider two frames S and S’ either stationary relative to each other or moving with a constant velocity relative to each other. A body which is stationary to an observer in frame S, will either appear to be stationary or will appear to be moving with a constant velocity to an observer in the frame S’ also. Ex; the force acting on the body for the observers of both the frames will be zero.

7. NON-INERTIAL FRAME OF REFERENCE The frames of reference in which Newton’s laws are not valid, are called non-inertial frames. All the accelerated and rotating frames are non-inertial. Since our earth rotates around its own axis, it is a non-inertial frame of reference.