## Kumar Ketan is teaching live on Unacademy Plus

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18.2k views unacademy Kumar Ketan Educator since January 2018 #6 years teaching experience #IIT JEE Physics #YouTuber (140k+ subs) #Unacademy educator(16k+ lifetimeviews) #Under graduate topper Follow me on the Unacademy Learning App 1k Followers Following Courses Get updates about new courses Watch all my lessons .Download slides and watch offline All courses HINDI Relative Motion (Hindi) Kinematics: Relative Motion Rain Drop and Boat River Proble.. 5.0 (5 ratings) Kumar Ketan Kumar Ketan

CRAs4 Physics course for IIT JEE Kinematics & Dynamics 1D Non-Accelerated Motion 1D Accelerated Motion Force Frictional Force Newton's Law of Motion Relative Motion

Points to Remember 'Displacement of a particle gives no information regarding the nature of the path followed by the particle. Motion with uniform velocity is on a straight line path. AT

For one dimensional motion the angle betweern a and v is either 0 or 180 . And it does not change with time. . For two dimensional motion, the angle between a and v is other than 0 or 180 . Also it may change with time

.If the angle between a and v is 0 or 180 the path of the particle is a straight line. .If the angle between a and v is other than 0 or 180 , the path of the particle is a curve. . If the angle between a and v is 90%, the path of the particle is a circle.

. For motion with constant acceleration the graph between x and t is a parabola. e In the above case the graph between v and t is a straight line. . Also in the above case, the graph between v and x is a parabola.

Which of the following time displacement graph is not possible in nature?

In graph (A), the velocity is infinite , which is practically impossible

Which of the following graphs represents the uniform motion ?

The distance time graph for uniform motion is a straight line inclined to both the time and distance axes

Which of the following distance time graphs represents one dimentional uniform motion?

ACCELERATED MOTION In non-uniform motion of an object, the velocity of the object is different at different instants, i.e., the velocity of the object keeps on changing with time. Such a motion is said to be an accelerated motion. For example, a vehicle while going from one position to another on a road, moves with different velocities at different instants, hence, it is the illustration of accelerated motion.

Acceleration is a vector quantity. It is positive if the velocity is increasing and is negative if the velocity is decreasing. The negative acceleration is also called a retardation or deceleration The unit of acceleration is in ms 2 in-mks system or SI and cms2 in CGS system. The dimensional formula acceleration is [M LT]

(c) Average acceleration- When an object is moving with a variable acceleration, then the average acceleration of the object for the givern motion is defined as the ratio of the total change in velocity of the object during motion to the total time taken, i.e.,

(d) Instantaneous acceleration when an object is moving with variable acceleration,men the object possesses different accelerations at different instants. The acceleration of the object at a given instant of time or at a given point of motion, is called its instantaneous acceleration.

Thus, the instantaneous acceleration of an object (1) is equal to the first time derivative of velocity at the given instant or (2) is equal to the second time derivative of position of the object at the given instant.